Hydrogen peroxide and glucose detection using surface plasmon resonance imaging biosensor with corrodible silver thin...

A surface plasmon resonance imaging (SPRI)-based biosensor is demonstrated for the detection of both hydrogen peroxide (H₂O₂) and glucose. The H₂O₂ to be detected acts as an oxidant and etch the silver film. This process gradually effects on resonance condition and consequently the reflected light intensity at a fixed angle. The etching rate of the silver film shows a clear relation with the H₂O₂ concentration. Therefore, monitoring the reflected light intensity progressively changing over a few minutes, enables accurate detection of H₂O₂ concentrations ranging from 0 to 200 μM (within physiological range of 0.25-50 μM), with a remarkable limit of detection (LOD) as low as 40 nM. In this regard, the behavior of the surface plasmon resonance (SPR) dip in response to the reduction of the silver film thickness is predicted by Winspall simulation software. These simulation results are in good agreement with the experimental results. Moreover, the proposed method can be applied to determine glucose concentrations ranging from 0 to 10 mM, encompassing the physiological range of 3-8 mM. This is achieved by observing the generated H₂O₂ through the enzymatic oxidation reaction between glucose and glucose oxidase (Gox). The sensor demonstrates remarkable sensitivity and selectivity, with a detection limit as low as 175 μM for glucose concentration. Furthermore, accurate measurement of glucose concentration in an actual human serum sample is achievable with the proposed sensor, using the standard addition method. The suggested glucose sensor shows promising prospects for use in routine glucose testing, employing a label-free, real-time, and multiplex detection approach.© 2017 Elsevier Inc. All rights reserved.