RESUMEN
Accumulation of heavy metals in humans and mammals causes health problems due to their abundance as transition metal ions. Iron (Fe2+) serves significantly in numerous biological processes as a heavy metal ion. In this study, we have designed and prepared a metal-organic framework (MOF) utilizing a one-step solvothermal process, incorporating a dual-ligand combination of terephthalic acid (H2BDC) and α,α',α''-tert-pyridine (TPY) with Eu3+ as the metal node. For this MOF, we termed it Eu-BDC/TPY. Eu-BDC/TPY has superior selectivity over other metal cations. It provides an accurate, sensitive, broad linear range colorimetric method for detecting Fe2+ in a concentration range of 1-50 µM with a modest limit of detection (0.33 µM). Eu-BDC/TPY detects the absence of Fe2+ quickly (within 5 seconds), which is very valuable in practical applications. In addition, the results can be used to create a digital image colorimetric card (DIC) using colorimetric software, enabling instantaneous detection of Fe2+ concentration using a smartphone.
RESUMEN
Biomarkers detection in blood with high accuracy is crucial for the diagnosis and treatment of many diseases. In this study, the proof-of-concept fabrication of a dual-mode sensor based on a single probe (Re-BChE) using a dual-signaling electrochemical ratiometric strategy and a "turn-on" fluorescent method is presented. The probe Re-BChE was synthesized in a single step and demonstrated dual mode response toward butyrylcholinesterase (BChE), a promising biomarker of Alzheimer's disease (AD). Due to the specific hydrolysis reaction, the probe Re-BChE demonstrated a turn-on current response for BChE at -0.28 V, followed by a turn-off current response at -0.18 V, while the fluorescence spectrum demonstrated a turn-on response with an emission wavelength of 600 nm. The developed ratiometric electrochemical sensor and fluorescence detection demonstrated high sensitivity with BChE concentrations with a low detection limit of 0.08 µg mL-1 and 0.05 µg mL-1, respectively. Importantly, the dual-mode sensor presents the following advantages: (1) dual-mode readout can correct the impact of systematic or background error, thereby achieving more accurate results; (2) the responses of dual-mode readout originate from two distinct mechanisms and relatively independent signal transduction, in which there is no interference between two signaling routes. Additionally, compared with the reported single-signal electrochemical assays for BChE, both redox potential signals were detected in the absence of biological interference within a negative potential window. Furthermore, it was discovered that the outcomes of direct dual-mode electrochemical and fluorescence quantifications of the level of BChE in serum were in agreement with those obtained from the use of commercially available assay kits for BChE sensing. This method has the potential to serve as a useful point-of-care tool for the early detection of AD.
Asunto(s)
Enfermedad de Alzheimer , Butirilcolinesterasa , Humanos , Enfermedad de Alzheimer/diagnóstico , Colorantes Fluorescentes , BiomarcadoresRESUMEN
The aims of the study described here were to illustrate the spectrum of ultrasonographic features of ductal carcinoma in situ (DCIS) and to evaluate the ability of ultrasonography (US) to predict the grade and recurrence of DCIS on the basis of mammographic and histopathologic findings. We retrospectively evaluated the ultrasonographic features of 129 DCIS lesions from 127 consecutive women and compared these with their mammographic and histopathologic features. The mean size of DCISs on ultrasonography and mammography (MMG) was 3.67 ± 1.40 and 4.00 ± 1.74 cm, respectively, which do not differ statistically (p = 0.09). Despite the statistical difference in Breast Imaging Reporting and Data System (BI-RADS) classification on US and MMG (p = 0.000), the median BI-RADS classification is category 4c on both US and MMG (p = 0.01). There was no statistically significant difference in the distribution of microcalcification on MMG and US. Clusters <5 mm in greatest diameter are easily seen on MMG. At US, a scattered/linear distribution on MMG had a higher level of visibility than clustered distribution on MMG. The correlation between tumor size and DCIS with micro-invasion evaluated using US is higher than that obtained using MMG (p = 0.001 and 0.024, respectively). When US was used for the detection of DCIS, diagnostic accuracy was significantly associated with higher Van Nuys groups, the presence of micro-invasion and comedo carcinoma (p = 0.000, 0.022 and 0.011, respectively). However, mammographic diagnostic accuracy was found not to associate with higher Van Nuys groups, the presence of micro-invasion and comedo carcinoma (p = 0.054, 0.093 and 0.256, respectively). Ultrasonography may play an important role both in detecting DCIS and in evaluating its histopathologic features. Detection of DCIS using MMG alone may be suboptimal for patients with dense breasts, especially among Chinese women.