Analyte-triggered autoacceleration of 4-mercaptophenylboronic acid-mediated aggregation of silver nanoparticles for facile and one-step ratiometric colorimetric method for detection of ascorbic acid

A simple, fast, one-step method is described for ratiometric colorimetric detection of ascorbic acid (AA) based on 4-mercaptophenylboronic acid (4-MPBA) and silver nanoparticles (AgNPs). In the presence of AA, the aggregation process of AgNPs can be triggered and accelerated, due to the interaction between 4-MPBA and the cis 1,2-diol moieties of AA through a reversible esterification, resulting in a distinguish color change from yellow to brownish red. The AA concentration-dependent color change can be quantified by the bare eyes or a UV–Vis spectrometer. The whole AA detection procedure was able to complete in 10 min with an excellent linear relationship (1–500 μM) and a low limit of detection (0.70 μM). The proposed approach was also used to accurately evaluate AA levels in orange juice. In our perception, this assay is rapid, sensitive, and specific, which demonstrates its potential on constructing biochemical and clinical sensors.