Self-assembled all-inclusive organic-inorganic nanoparticles enable cascade reaction for the detection of glucose

Traditional colorimetric glucose biosensor generally involves complex assay procedures. Free labile enzymes and peroxidase substrates are used separately for triggering a chromogenic reaction. These limits result in inferior enzyme stability and defective enzymatic catalytic efficiency, making it hard to routinely utilize them for the direct and fast test of glucose. In this work, we provide an all-inclusive substrates/enzymes nanoparticle employed 3,3'5,5'-tetramethylbenzidine (TMB) as chromogenic substrates and glucose oxidase (GOx)/horseradish peroxidase (HRP) as signal amplifier enzymes (TMB-GH NPs) by the molecule self-assembly technique. The all-inclusive nanoparticles can realize the tandem colorimetric reactions, and the oxidation product of TMB (ox-TMB) exhibits a strong NIR laserdriven photothermal effect, thus allowing quantitative photothermal detection of glucose. Owing to the restriction of the molecular motion of GOx, HRP, and TMB, the distance of mass transfer between substrates was shortened largely, leading to improved catalytic activity for glucose. Overall, our strategy will simplify the analysis procedure, furthermore, these integrated nanoparticles not only display higher stability and activity than that of the free GOx/HRP system and possesses an excellent performance for colorimetric and photothermal bioassay of glucose simultaneously. We believe that this unique technique will give good inspirations to develop simple and precise methods for bioassay. (C) 2021 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.

Automated summary

This study presents an all-inclusive nanoparticle system for colorimetric and photothermal bioassay of glucose. The nanoparticles utilize TMB as chromogenic substrates and GOx/HRP as signal amplifier enzymes, demonstrating improved enzymatic catalytic efficiency and stability compared to traditional methods. The incorporation of NIR laser-driven photothermal effects allows for quantitative photothermal detection of glucose. This unique technique holds promise for developing simple and precise bioassay methods.