One-component dual-mode sensor array for identification and quantification of biothiols.

Biothiol analysis is significant to health assessment and early detection of potential diseases. Considering practical requirements, simple and rapid identification and determination of biothiols are still a great challenge due to the similar structures. Fortunately, the recently emerging colorimetric sensor array technique makes such a task possible. Herein, one-component dual-mode sensor array consisting of carbon dots (CDs) and Ag nanoparticles (AgNPs) system was designed for identification and quantification of biothiols. The identification principle is based on the inner filter effect (IFE) and different binding constants. Due to the IFE between CDs and AgNPs, the fluorescence of CDs was quenched, but recovered again after addition of biothiols because of the binding of biothiols with AgNPs. Significantly, the fluorescence recovered in varying degree due to the different binding constants of biothiols to AgNPs. Meanwhile, the absorbance of the system decreased and the color of the solution deepened. Therefore, the CDs-AgNPs system with fluorescence and absorbance response was used as the single sensing unit and generated the cross-responsive signal for different biothiols. The sensor array achieved 100 % accuracy in identifying biothiols and biothiol mixtures. Moreover, the rapid quantification of biothiols in serum samples was also achieved by RGB-based smartphone colorimetry. The way to construct one component sensor array with dual mode signal outputs tremendously saves cost and time, providing a powerful tool for the identification of different biothiols. In addition, the rapid quantification of biothiols in serum samples based on RGB-based smartphone colorimetry demonstrated its powerful application prospects in disease diagnosis.