RESUMO
Graphene and its derivatives are in the edge of technology with a wide and diverse range of applications. In the last years, especially graphene quantum dots (GQDs) have had their biomedical application expanded in scope, mainly focused on cancer therapy, drug delivery and imaging. Although many studies have evaluated the application of this nanomaterial in biomedical field, only a few studies aimed to understand their biological impact in human health. In this regard, here we evaluated the impact of high doses of GQDs on the microcirculation of a healthy animal model to better assess risks of its use in humans. Our data show that successive applications of GQDs cause irreversible damage to the microcirculation. After seven days, a complete destruction of the microcirculation has been observed. In addition, GQDs showed substantial activity in human erythrocytes. Our findings suggest that risks associated with the use of GQDs, as well as all graphene derivatives, must be better understood, especially concerning biomedical application. A greater understanding of how GQDs impact body circulation, including the context of environmental and engineered nanosystems, is of paramount importance.
Assuntos
Grafite , Nanoestruturas , Pontos Quânticos , Animais , MicrocirculaçãoRESUMO
A new disposable microfluidic electrochemical paper-based device (ePAD) consisting of two spot sensors in the same working electrode for the simultaneous determination of uric acid and creatinine was developed. The spot 1 surface was modified with graphene quantum dots for direct uric acid oxidation and spot 2 surface modified with graphene quantum dots, creatininase and a ruthenium electrochemical mediator for creatinine oxidation. The ePAD was employed to construct an electrochemical sensor (based on square wave voltammetry analysis) for the simultaneous determination of uric acid and creatinine in the 0.010-3.0⯵molâ¯L-1 range. The device showed excellent analytical performance with a very low simultaneous detection limit of 8.4 nmol L-1 to uric acid and 3.7 nmol L-1 to creatinine and high selectivity. The ePAD was applied to the rapid and successful determination of those clinical biomarkers in human urine samples.