TMBvsABTS: comparison of multi‐enzyme‐based approaches for the colorimetric quantification of salivary glucose

Abstract BACKGROUND Diabetes is one of the fastest‐growing health problems of recent times. Its diagnosis, monitoring and control are carried out mainly by glucose quantification in blood samples, which can be a traumatic and painful procedure for many patients. Saliva is an emerging diagnostic biofluid for minimally invasive disease diagnosis. Its collection can be performed through a simple, noninvasive and painless procedure that does not require qualified personnel. This project aimed to develop, standardize and compare two enzyme‐based approaches (TMB and ABTS) for the colorimetric quantification of salivary glucose. RESULTS The obtained results with both dyes revealed the suitability of these systems for glucose quantification under buffer conditions, displaying excellent linearity ( R 2 > 0.99) and precision (CV < 1%), and high glucose specificity. Furthermore, the TMB system was able to quantify not only glucose in human saliva samples, showing a low read‐out variability (CV < 3%), but also glucose changes (16 and 50 μmol L −1 ) with low variability (CV < 4.2%) and excellent recovery (96–103%), which is important in clinical diagnosis. CONCLUSION Altogether these results demonstrated the capacity of the approaches in quantifying glucose either in buffer (using both TMB ans ABTS) or in human saliva samples (using TMB). They offer a painless, simple, efficient, and relatively inexpensive analytical method with enormous potential for the diagnosis and monitoring of diabetes using a small amount of saliva. © 2022 Society of Chemical Industry (SCI).