An elaborate composite of molecularly imprinted polymer (MIP)-modified gold nanoparticles (AuNPs)@silica dioxide (SiO2) was designed and prepared for real-time colorimetric determination of glutathione (GSH) in serum. Firstly, the MIPs were synthesized on the surface of SiO2 utilizing GSH as template molecules. Then, AuNPs were synthesized on the surface of MIPs@SiO2 to produce a composite of MIPs modified by AuNPs@SiO2. Compared with plain AuNPs, the composite possessed better peroxidase catalysis activity due to stabilization and protection from hydrophilic SiO2, which can catalyze H2O2 to·OH oxidizing 3,3,5,5-tetramethylbenzidine (TMB) to the colored product. In addition, its selectivity was enhanced by MIP modification with special recognition cavities. With the composite as the sensor, GSH was precisely and sensitively detected in the range 5 ~ 40 μM with a limit of determination of 1.16 μM according to the principle of inhibitive peroxidase catalysis activity by GSH. The proposed colorimetric detection was successfully utilized for selective, convenient, and rapid determination of GSH in serum. It provided a new strategy for drug real-time monitoring and has high potential in clinical drug analysis.
Keywords: AuNPs; Colorimetry; Glutathione; Molecularly imprinted polymers; Nanozyme; Photometry.
© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.