Silicene's intriguing nanozymatic activity: Improved colorimetric and electrochemically supported colorimetric biosensing

Abstract

Silicene is a material that is largely studied via theoretical models. In the practical world, lengthy incubation times and poor sensitivity of colorimetric detection methods have limited their implementation. This paper transforms silicene's theoretical advantages into practical applications, presenting it as a tangible solution for significantly improving colorimetric biosensing. More specifically, this paper presents a pivotal breakthrough by not only documenting the remarkable nanozymatic activity of silicene in oxidizing 3,3′,5,5′-Tetramethylbenzidine (TMB) with hydrogen peroxide (H2O2), but also leveraging silicene’s inherent electronic properties to enhance the speed and precision of the peroxidase reaction, thereby improving its performance and advancing applicability. Two detection mechanisms were tested to observe the influence of silicene’s electronic scope; one in the absence and the other in the presence of an externally supplied electric potential. Both were successful in the detection of H2O2 and dopamine. The latter proved to be more favorable as it not only shortened the incubation time from 30 min to 1.5 min but also exhibited lower Limit of Detection (LOD) values. To demonstrate, for dopamine, in a concentration range of 0 – 10 μM, the LOD was 4.13 μM without the electric potential and 2.21 μM with the electric potential. Similarly, in a second concentration range, the LOD values were 37.81 μM and 34.94 μM, respectively. Kinetic profiles indicated the superior affinity silicene has for TMB and H2O2. A selectivity test also indicated that the method has excellent selectivity towards dopamine.