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Dual-mode optical imaging can simultaneously provide morphological and functional information. Furthermore, it can be integrated with projection mapping method to directly observe the images in the region of interest. This study was aimed to develop a dual-mode optical projection mapping system (DOPMS) that obtains laser speckle contrast image (LSCI) and subcutaneous vein image (SVI) and projects onto the region of interest, minimizing the spatial misalignment between the regions captured by the camera and projected by a projector. In in vitro and in vivo studies, LSCI and SVI were obtained and projected under single-mode illumination, where either the laser or light-emitting diode (LED) was activated, and under dual-mode illumination, where the laser and LED were activated simultaneously. In addition, fusion image (FI) of LSCI and SVI was implemented to selectively observe blood perfusion in the vein. DOPMS successfully obtained LSCI, SVI, and FI and projected them onto the identical region of interest, minimizing spatial misalignment. Single-mode illumination resulted in relatively clearer and noise-free images. Dual-mode illumination introduced speckle noise to SVI and FI but enabled real-time imaging by simultaneously employing LSCI, SVI, and FI. FI may be more effective for quasi-static evaluations before and after treatment under single-mode illumination and for real-time evaluation during treatment under dual-mode illumination owing to its faster image processing, albeit with a potential tradeoff in image quality.

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While spatial and time-resolved anti-counterfeiting technologies have gained increasing attention owing to their excellent tunable photoluminescence, achieving high-security-level anti-counterfeiting remains a challenge. Herein, we developed a spatial-time-dual-resolved anti-counterfeiting system using zero-dimensional (0D) organic-inorganic Mn(II) metal halides: (EMMZ)2MnBr4 (named M-1, EMMZ=1-Ethyl-3-Methylimidazolium Bromide) and (EDMMZ)2MnBr4 (named M-2, EDMMZ=1-Ethyl-2,3-Dimethylimidazolium Bromide). M-1 shows a bright green emission with a quantum yield of 78 %. It undergoes a phase transformation from the crystalline to molten state with phosphorescence quenching at 350 K. Reversible phase and luminescent conversion was observed after cooling down for 15 s. Notably, M-2 exhibits green light emission similar to M-1 but undergoes phase conversion and phosphorescence quenching at 390 K, with reversible conversion observed after cooling down for 5 s. The photoluminescence switching mode of on(green)-off-on(green) can be achieved by temperature control, demonstrating excellent performance with short response times and ultra-high cyclic reversibility. By leveraging the different quenching temperatures and reversible PL conversion times of M-1 and M-2, we propose a spatial-time-dual-resolved photoluminescence (PL) switching system that combines M-1 and M-2. This system enables multi-fold tuning of the PL switch for encryption and decryption through cationic engineering strategies by modulating temperature and cooling time. This work presents a novel and feasible design strategy for advanced-level anti-counterfeiting technology based on a spatial-time-dual-resolved system.

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The comprehensive determination of fatty acids without derivatization, including short-chain fatty acids (SCFAs), medium-chain fatty acids (MCFAs) and long-chain fatty acids (LCFAs), is a big challenge but powerful for lipidomics in biology, food, and environment. Herein, the dual mode unity solid-phase microextraction (DMU-SPME) combined with gas chromatography-flame ionization detector (GC-FID) or mass spectrometry (MS) was proposed as a powerful method for the determination of comprehensive free fatty acids in real samples. Under the optimized DMU-SPME conditions, the proposed method has good linearity (R2 ≥ 0.994) and low limits of determination (0.01-0.14 mg/L). In the stability analysis, the intra-day relative standard deviation was 1.39-12.43 %, and the inter-day relative standard deviation was 2.84-10.79 %. The recoveries of selected 10 fatty acids in real samples ranged from 90.18 % to 110.75 %, indicating that the method has good accuracy. Fatty acids ranging from C2 to C22 were detected in real samples by the untargeted determination method of DMU-SPME combined with gas chromatography-mass spectrometry (GC-MS). The DMU-SPME method proposed in this study can be used for lipid metabolism analysis and free fatty acid determination in the fields of biology, food, and environment.

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In the present research, Fe-based metal-organic frameworks (MIL-101(Fe)-NH2) nanoparticles were synthesized by simple solvothermal methods and used to assay Cr(Ⅵ). The MIL-101(Fe)-NH2 performs dual functions: the 2-aminoterephthalic acid (NH2-BDC) ligand endows a strong fluorescence emission, and the Fe metal nodes are able to facilitate the oxidation of 3,3',5,5'- tetramethylbenzidine (TMB) directly, resulting in the generation of oxidized-TMB (ox-TMB). Our research results showed that reducing agents such as ascorbic acid (AA) can collapse the structures of MIL-101(Fe)-NH2 because of the reduction of Fe3+ by AA, resulting in release of NH2-BDC. In the presence of Cr(Ⅵ), the fluorescence intensity of the MIL-101(Fe)-NH2 + AA system will be decreased due to the competitive reduction of Fe3+ and Cr(Ⅵ). Nevertheless, Cr(Ⅵ) can significantly accelerate the oxidation of TMB by MIL-101(Fe)-NH2 as it boosts the electron transfer rate between Fe3+ and Fe2+. Therefore, a fluorescent/colorimetric dual-mode platform was developed for the detection of Cr(Ⅵ) with an extensive linear range (7.5-750 µg/L and 13.3-1000 µg/L) as well as a remarkably low detection limit (0.99 µg/L and 1.98 µg/L). This MOF with the ability to release ligands not only provides inspiration for the design of new luminescent materials, but also offers a novel and reliable solution for the detection of Cr(Ⅵ).

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BACKGROUND: Salmonella Typhimurium poses a serious threat to human health worldwide, necessitating the development of a rapid, sensitive, and convenient method for S. Typhimurium detection. Nanozymes are considered ideal signal report elements, which are extensively used for developing colorimetric methods. However, single-component nanozymes display low catalytic activity, and colorimetric methods are susceptible to environmental interference, reducing the sensitivity and accuracy of detection results. To address these drawbacks, this study constructed a dual-mode composite nanozyme-based cascade colorimetric-fluorescence aptasensor for S. Typhimurium detection in food. RESULTS: In this study, the composite Fe3O4@MIL-100(Fe) nanozymes were successful synthesized and demonstrated substantial peroxide-like activity, with 4.76-fold higher specificity activity (SA) than that of Fe3O4 nanozymes. Then, a glucose oxidase (GOx)-Fe3O4@MIL-100(Fe) cascade reaction was developed for colorimetric detection via an aptamer to facilitate the formation of Fe3O4@MIL-100(Fe)/S. Typhimurium/carboxylated g-C3N4 (CCN)-GOx sandwich complexes. Meanwhile, the fluorescence mode was achieved by measuring the fluorescence intensity of the sandwich complexes. In optimum conditions, the dual-mode detection limits (LOD) were 1.8 CFU/mL (colorimetric mode) and 1.2 CFU/mL (fluorescence mode), respectively, with the S. Typhimurium concentration ranging from 10 CFU/mL to 107 CFU/mL. Finally, the feasibility of the dual-mode colorimetric-fluorescence method was validated via three actual samples, yielding recovery rates of 77.32 % to91.17 % and 82.17 % to 103.7 %, respectively. SIGNIFICANCE AND NOVELTY: This study successfully develops a composite nanozyme-based cascade colorimetric and fluorescence dual-mode aptasensor for S. Typhimurium detection. It presents several distinct benefits, such as a broader linear range (10-107 CFU/mL), a lower LOD value (1.2 CFU/mL), and more accurate results. More importantly, the proposed dual-mode method displays a low LOD in colorimetric mode, demonstrating considerable potential for S. Typhimurium on-site detection in food.

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Salmonella enteritidis (SE) is a food-borne pathogens that can cause acute gastroenteritis. With the increasing social attention to food safety, the detection method of SE has attracted wide attention. In response to the demand for efficient detection methods of SE, this study constructed a novel dual-mode photoelectrochemical-electrochemical (PEC-EC) aptamer-based biosensor. The sensor was constructed using Bi4NbO8Cl/In2S3 heterojunction as the electrode substrate material, the hybridization chain reaction (HCR) and dye sensitization were used as the signal amplification strategies. Bi4NbO8Cl/In2S3 heterojunction could provide an excellent initial photocurrent response for the sensing platform, and the HCR was opened by the end of complementary DNA (cDNA) and generated an ultra-long DNA double-stranded (dsDNA) "super structure" on the surface of the electrode, which could be embedded with a large number of methylene blue (MB) as the bifunctional probes. Thus, dual-mode output was achieved via the PEC and EC activity of MB. Under the optimized conditions, the PEC and EC signal responses of the system were linear to the logarithm of SE concentration in a range from 1.5 × 102 CFU/mL to 1.5 × 107 CFU/mL. The detection limits were found to be 12.9 CFU/mL and 12.3 CFU/mL using the PEC and EC methods, respectively. The constructed dual-mode biosensor exhibited good performance for real sample analysis, and demonstrated great application potential in the field of SE rapid detection. Moreover, this dual-mode detection strategy provided more accurate and reliable results than the single-mode output.

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Conductive gel interface materials are widely employed as reliable agents for electroencephalogram (EEG) recording. However, prolonged EEG recording poses challenges in maintaining stable and efficient capture due to inevitable evaporation in hydrogels, which restricts sustained high conductivity. This study introduces a novel ion-electron dual-mode conductive hydrogel synthesized through a cost-effective and streamlined process. By embedding graphite nanoparticles into ionic hyaluronic acid (HAGN), the hydrogel maintains higher conductivity for over 72 h, outperforming commercial gels. Additionally, it exhibits superior low skin contact impedance, considerable electrochemical capability, and excellent tensile and adhesion performance in both dry and wet conditions. The biocompatibility of the HAGN hydrogel, verified through in vitro cell viability assays and in vivo skin irritation tests, underscores its suitability for prolonged skin contact without eliciting adverse reactions. Furthermore, in vivo EEG tests confirm the HAGN hydrogel's capability to provide high-fidelity signal acquisition across multiple EEG protocols. The HAGN hydrogel proves to be an effective interface for prolonged high-quality EEG recording, facilitating high-performance capture and classification of evoked potentials, thereby providing a reliable conductive medium for EEG-based systems.

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Dual-mode readout platforms with colorimetric and electrochemiluminescence (ECL) signal enhancement are proposed for the ultrasensitive and flexible detection of the monkeypox virus (MPXV) in different scenes. A new nanotag, Ru@U6-Ru/Pt NPs is constructed for dual-mode platforms by integrating double-layered ECL luminophores and the nanozyme using Zr-MOF (UiO-66-NH2) as the carrier, which not only generates enhanced ECL and colorimetric signals but also provide greater stability than that of commonly used nanotags. Dual-mode platforms are used within 15 min from the "sample in" to the "result out" steps, without nucleic acid amplification. The colorimetric mode allows the screening of MPXV with the visual limit of detection (vLOD) of 0.1 pM (6 × 108 copies µL-1) and the ECL mode supports quantitative detection of MPXV with an LOD as low as 10 aM (6 copies·µL-1), resulting in a broad sensing range of 60 to 3 × 1011 copies·µL-1 (10 orders of magnitude). Validation is conducted using 50 clinical samples, which is 100% concordant to those of quantitative polymerase chain reaction (qPCR), indicating that Ru@U6-Ru/Pt NPs-based dual-mode sensing platforms showed great promise as rapid, sensitive, and accurate tools for diagnosis of the nucleic acid of MPXV and other infectious pathogens.

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Non-contact temperature sensors utilising the fluorescence intensity ratio and the unique up-conversion (UC) luminescence of rare-earth ions have numerous benefits; however, their operational temperature range has remained limited. In this study, NaLuF4:Yb3+/Ho3+ samples were prepared by the hydrothermal method. The samples exhibited exceptional UC luminescence properties at low temperatures. The intensity of the green emission (with peak wavelengths of 540 and 546 nm) gradually decreased with increasing temperature, and the green emissions showed a unique change at low temperatures. In addition, we studied the dependence of the UC luminescence intensity on the excitation power and the variation in the decay lifetime with temperature. The experiments revealed excellent luminous performance and significantly enhanced sensitivity at low temperatures; the maximum absolute sensitivity Sa and relative sensitivity Sr of the 540 and 546 nm thermally coupled energy levels were 1.02% and 0.55% K-1, respectively. The potential temperature sensing properties of Yb3+/Ho3+-co-doped NaLuF4 makes it suitable for temperature sensing applications at temperatures as low as 30 K. This study offers a novel approach for the advancement of temperature sensing technology at low temperatures.

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BACKGROUND: NO2- and S2- are two kinds of common toxic anions widely distributed in environmental water, soil and food products. Human beings have suffered a lot of diseases from intake of excessive NO2- or S2-, i.e., infantile methemoglobin, cancer and even to death. Although tremendous efforts have been afforded to monitor NO2- and S2-, most were high instrument-depended with complex processing procedures. To keep food safety and to protect human health, it will be a huge challenge to develop a convenient and efficient way to monitor S2- and NO2- in practice. RESULTS: A kind of folic acid capping Bi3+-doped Ag quantum dots (FA@Bi3+-Ag QDs) was developed for the first time by one-pot homogeneous reduced self-assembly. Not only did FA@Bi3+-Ag QDs possess intrinsic fluorescent property, it expressed synergistic peroxidase-like activity to catalyze the redox of 3,3',5,5'-tetramethylbenzidine (TMB) and H2O2 with Km/vmax of 0.087 mM/6.61 × 10-8 M s-1 and 6.42 mM/6.25 × 10-7 M s-1 respectively. Interestingly, trace S2- could exclusively alter its fluorescent property and peroxidase-like activity, exhibiting significant hypochromic and "turn-on" fluorescent effects. While trace NO2- could make FA@Bi3+-Ag QDs-TMB-H2O2 system hyperchromic. Under the optimized conditions, FA@Bi3+-Ag QDs were applied for dual-mode recognition of S2- and visual sensing of NO2- in real food samples with satisfactory recoveries, i.e., 100.7-107.9 %/95.8-104.7 % and 97.2-104.8 % respectively. The synergistic enzyme-mimic mechanism of FA@Bi3+-Ag QDs and its selective response mechanisms to S2- and NO2- were also proposed. SIGNIFICANCE: This represents the first nanozyme-based FA@Bi3+-Ag QDs system for dual-mode recognition of S2- and visual sensing of NO2-, well meeting the basic requirement in drinking water set by WHO. It will offer a promising way for multi-mode monitoring of different pollution using the same nanozyme-based sensor.

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Excessive use of antibiotics will enter the water environment and soil through the biological chain, and then transfer to the human body through food, resulting in drug resistance, kidney toxicity and other health problems, so it is urgent to develop highly sensitive detection methods of antibiotics. Here, we designed a dual-mode sensor platform based on closed bipolar electrode (cBPE) electroluminescence (ECL) and mobile phone imaging to detect kanamycin in seawater. The prepared CN-NV-550 displayed extremely intense ECL signal, allowing for convenient mobile phone imaging. The cBPE was combined with DNA cycle amplification technology to prevent the mutual interference between target and the luminescent material, and realized the amplification of signal. In the presence of target Kana, Co3O4 was introduced to the cBPE anode by DNA cycle amplification product, and accelerated the oxidation rate of uric acid (UA). Thus, the electroluminescence response of CN-NV-550 on cBPE cathode was much improved due to the charge balance of the cBPE, achieving both ECL detection and mobile phone imaging assay of Kana, which much improved the accuracy and efficiency of assay. The limit of detection (LOD) in this work is 0.23 pM, and LOD for mobile phone imaging is 0.39 pM. This study integrate ECL imaging visualization of CN-NV-550 and high electrocatalytic activity of Co3O4 into cBPE-ECL detection, providing a new perspective for antibiotic analysis, and has great potential for practical applications, especially in Marine environmental pollution monitoring.

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Dual-mode signal output platforms have demonstrated considerable promise due to their improved anti-interference capability and inherent signal self-correction. Nevertheless, traditional discrete-distributed signal probes often encounter significant drawbacks, including limited mass transfer efficiency, diminished signal strength, and instability in intricate biochemical environments. In response to these challenges, a scalable and hyper-compacted 3D DNA nanoplatform resembling "periodic focusing heliostat" has been developed for synergistically enhanced fluorescence (FL) and surface-enhanced Raman spectroscopy (SERS) biosensing of miRNA in cancer cells. Our approach utilized a distinctive assembly strategy integrating gold nanostars (GNS) as fundamental "heliostat units" linked by palindromic DNA sequences to facilitate each other hand-in-hand cascade alignment and condensed into large scale nanostructures. This configuration was further augmented by the incorporation of gold nanoparticles (GNP) via strong Au-S bonds, resulting in a sturdy framework for improved signal transduction. The initiation of this assembly process was mediated by the hybridization of dsDNA to miRNA-21, which served as a primer for polymerization and nicking reactions, thus generating a multifunctional T2 probe. This probe is intricately designed with three distinct parts: a 3'-palindromic end for structural integrity, a central region for capturing SERS-active probes (Cy3-P2), and a 5'-segment for attaching fluorescence reporters. Upon integration T2 into the GNS-based heliostat unit, it promotes palindromic arm-induced aggregation and plasma exciton coupling between plasma nanoparticles and signal transduction tags. This clustered arrangement creates a high-density "hot spot" array that maximizes the local electromagnetic fields necessary for enhanced SERS and FL response. This superstructure supports enhanced aggregation-induced signal amplification for both SERS and FL, offering exceptional sensitivity with LOD as low as 0.0306 pM and 0.409 pM. The efficacy of this method was demonstrated in the evaluation of miRNA-21 in various cancer cell lines.

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This study investigates the dynamic characteristics of the dual-mode resonant non-linear Schrodinger equation with a Bhom potential. Hydrodynamics, nonlinear optical fibre communication, elastic media, and plasma physics are just a few of the mathematical physics and engineering applications for this model. The study aims to achieve two main objectives: first, to discuss bifurcation analysis, and second, to extract optical soliton solutions using the extended hyperbolic function method. The study successfully derives various wave solutions, including bright, singular, periodic singular and dark solitons, based on the governing model. The findings conferred in this article show a crucial advancement in understanding the propagation of waves in non-linear media. Additionally, bifurcation of phase portraits of ordinary differential equation consistent with the partial differential equation under consideration is conducted. We also highlight specific constraint conditions that ensure the presence of these obtained solutions. The existing literature shows that these methods are first time applied on this model.

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Surface wrinkling structures based on a bilayer system are widely employed in storing and encrypting specific optical information. However, constructing a stable wrinkling structure with high-level security remains an extensive challenge due to the delamination issue between the skin layer and the substrate. Herein, a double cross-linking strategy is introduced between a hydrogel layer doped with fluorescent molecules and polydimethylsiloxane to establish a stable interfacial wrinkling structure with dual-mode functionality, in which the light reflection of the wrinkles and fluorescence intensity of fluorescent molecules can be simultaneously regulated by the modulus ratio between the two layers. The spontaneous wrinkling structures with a physically unclonable function can enhance the photoluminescence emission intensity of the wrinkling area under ultraviolet radiation. Meanwhile, the skin layer constructed of acrylamide and acrylic acid copolymer protects the interfacial wrinkling patterns from the loss of a detailed structure for authentication due to external damage. The stable interfacial wrinkling structures with fluorescence can find potential applications in the fields of information storage and encryption.

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Dual-mode humidity sensors have received wide attention in recent years due to their great potential in multifunction applications. Herein, following a "two birds with one stone" strategy, a dual-mode and self-powered low humidity sensor based on LiBr-MOF-801 with high response and power generation is proposed. The optimized LiBr-MOF-801-based sensor exhibits impedance-voltage dual-mode sensitivity in the low humidity range of 0-23% relative humidity (RH) with high response (57.1 and 0.61 V), small hysteresis (0.3% RH) and good long-term stability at room temperature (20 °C). Moreover, an integrated humidity power generator is obtained by series connection of the self-powered humidity sensor within 15 cm2, and the output voltage reaches 2.6 V with an output power density of 110 nW cm-2, and can be used as energy, supplying power to commercial electronic equipment even in low humidity. This work provides a new sight for fabricating high-performance, dual-mode, and self-powered low-humidity sensors.

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A fluorescent-colorimetric dual-signal platform, N, S co-doped carbon dots functionalized silver nanoparticles (NS-CDs-AgNPs), was designed in situ by reducing AgNO3 in the presence of N, S co-doped carbon dots (NS-CDs) under the assistance of microwave irradiation for glucose determination. With the formation of silver nanoparticles (AgNPs), the intrinsic fluorescence of NS-CDs was quenched, showing the fluorescence state was off. Whereas the fluorescence of NS-CDs can be switched on when a trace amount of H2O2 was added. Based on this novel phenomenon, the peroxidase-like activity of NS-CDs-AgNPs by using 3,3',5,5'-tetramethylbenzidine (TMB) chromogen and H2O2 as substrates was evaluated. The Km values of the prepared probe for H2O2 and TMB were 0.84 mM and 0.01 mM with the Vm of 6.65 × 10-8 M S-1 and 3.01 × 10-8 M S-1, respectively. The results showed that NS-CDs-AgNPs had good peroxidase-like activity and strong affinity to TMB and H2O2. It confirmed that there is a redox interaction between AgNPs and H2O2, and H2O2 can oxidize Ag to produce Ag+, which is the main reason that the fluorescence of NS-CDs-AgNPs can be activated by H2O2. The hydroxyl radical (·OH) was formed in the process of reaction, which can further oxidize TMB for color reaction. Meanwhile, glucose can be oxidized to produce H2O2 in the presence of glucose oxidase (GOx). Based on the phenomenon, a fluorimetric and colorimetric dual-mode sensor for glucose detection was established. Satisfactory results were obtained with the linear range of 0.1-80 µM for fluorimetric mode and 0.5-5 µM for colorimetric mode, respectively. Additionally, the LOD was below 0.32 µM and 0.21 µM, respectively. The method was successfully applied to determine the glucose in human serum with satisfactory recovery and RSD.

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The use of music as an aid to recovery during and after exercise is an area of growing scientific interest. We investigated the effects of in-task, asynchronous music and respite-active music (i.e., music used for active recovery in between high-intensity exercise bouts) on a range of psychological, psychophysical and psychophysiological outcomes. Participants (N = 28; 14 females) made five laboratory visits for: (a) pre-test/familiarisation; (b) fast-tempo music during supramaximal exercise bouts and medium-tempo music during active-recovery periods; (c) fast-tempo music during exercise and no music during recovery; (d) no music during exercise and medium-tempo music during recovery; and (e) a no-music (throughout) control. A cycle ergometer-based HIIT protocol comprising 6 × 60-s bouts at 100% Wmax with 75-s active recovery was administered. Measures were taken at the end of supramaximal bouts and active recovery periods (RPE, state attention, core affect, state motivation), then upon cessation of the protocol (remembered pleasure and exercise enjoyment). Heart rate and heart rate variability (HRV) measures were taken throughout. The music manipulations only had an effect on state motivation, which was higher (p = 0.036) in the fast tempo-medium tempo condition compared to no-music control (Cohen's d = 0.49), and the SDNN component of HRV, which was lower (p = 0.007) in the fast-tempo-no-music condition compared to control (Cohen's d = 0.32). Collectively, the present findings do not support any of the study hypotheses regarding the music-related manipulations, and do not concur with the findings of related studies (e.g., Karageorghis et al., 2021). The unexpected results are discussed with reference to extant theory, and recommendations are offered in regard to music-related applications.

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Self-powered photoelectrochemical (PEC) sensing is a novel sensing modality. The introduction of dual-mode sensing and photoelectrocatalysis in a self-powered system enables both detection and sterilization purposes. To this end, herein, a self-powered multifunctional platform for the photoelectrochemical-fluorescence (PEC-FL) detection and in-situ inactivation of Salmonella enteritidis (SE) was constructed. The platform utilized Bi4NbO8Cl/V2CTx/FTO as a photoanode and CuInS2/FTO as a photocathode and incubated quantum dot (QDs) signaling probes on the surface of the photocathode. During detection, the system drives the transfer of photogenerated electrons between the dual photoelectrodes through the Fermi energy level difference. The photoanode amplifies the photoelectric signal, while the photocathode is solely dedicated to the immune recognition process. QDs provide an additional fluorescence signal to the system. Under optimal experimental conditions, the multifunctional platform achieves detection limits of 3.2 and 5.3 CFU/mL in PEC and FL modes respectively, with a detection range of 2.91 × 102 to 2.91 × 108 CFU/mL. With the application of an external bias voltage, it further promotes electron transfer between the dual photoelectrodes, inhibits the recombination of photogenerated electrons and holes. It generates a significant amount of superoxide radicals (·O2-) in the cathodic region, resulting in strong sterilization efficiency (99%). The constructed self-powered multifunctional platform exhibits high sensitivity and sterilization efficiency, it provides a feasible and effective strategy to enhance the comprehensive capability of self-powered sensors.

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The detrimental growth of water pollutants such as heavy metals has become a life-threatening problem in the modern era. Challenges remain in the development of rapid and accurate methods for detecting pentavalent arsenic [As(V)] in environmental water. The octahedral Mn3O4 nanoparticles (NPs) did not display excellent laccase-mimicking catalytic activity, whereas the adsorbed As(V) on the surface significantly enhanced the catalytic activity. Meanwhile, the quinone imine generated from the substrates 2,4-dichlorophenol (2,4-DP) and 4-aminoantipyrine (4-AAP) catalyzed by octahedral Mn3O4 NPs further quenched the carbon dots fluorescence. Thus, it is possible to establish a fast and accurate dual-mode sensor for detecting As(V). The developed dual-mode method of As(V) detection has good sensitivity and selectivity. The limit of detection for As(V) in colorimetric mode is 6.96 µg·L-1, whereas in the fluorescent mode, it is as low as 2.56 µg·L-1. Moreover, the detection data obtained by the dual-mode method can be validated by each other, thereby ensuring the dependability of the sensing system. The constructed dual-mode method with merits of sensitivity, speed and accuracy can offer a powerful tool for As(V) detection in environmental water. Furthermore, the application of laccase-mimicking activity in dual-mode detection provides new strategies for other environmental hazard detection.

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The opportunistic human pathogen Pseudomonas aeruginosa (P. aeruginosa) poses a significant threat to human health, causing sepsis, inflammation, and pneumonia, so it is crucial to devise an expeditious detection platform for the P. aeruginosa. In this work, bis (2- (3, 5- dimethylphenyl) quinoline- C2, N') (acetylacetonato) iridium (III) Ir (dmpq)2 (acac) with excellent electrochemiluminescence (ECL) and fluorescence (FL) and magnetic nanoparticles were encapsulated in silica spheres. The luminescent units exhibited equal ECL and FL properties compared with single iridium complexes, and enabled rapid separation, which was of vital significance for the establishment of biosensors with effective detection. In addition, the luminescent units were further reacted with the DNA with quenching units to obtain the signal units, and the ECL/FL dual-mode biosensor was employed with the CRISPR/Cas12a system to further improve its specific recognition ability. The ECL detection linear range of as-proposed biosensor in this work was 100 fM-10 nM with the detection limit of 73 fM (S/N = 3), and FL detection linear range was 1 pM-10 nM with the detection limit of 0.126 pM (S/N = 3). Importantly, the proposed dual-mode biosensor exhibited excellent repeatability and stability in the detection of P. aeruginosa in real samples, underscoring its potential as an alternative strategy for infection prevention and safeguarding public health and safety in the future.

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