Salivary Glucose Detection with Laser Induced Graphene/AgNPs Non-Enzymatic Sensor

Abstract

The tailoring of novel nanomaterials for sensitive glucose detection through a non-enzymatic mechanism is currently under intensive research. Here, we present a laser-induced graphene (LIG) electrode decorated with silver nanoparticles (AgNPs) as a catalytic element for the direct electrooxidation of glucose. The AgNPs were synthesized through cyclic voltammetry using LIG as a template, resulting in a porous tridimensional assembly with anchored nanostructures. The characterization corroborated the formation of LIG/AgNPs composite with distinctive peaks attributed to Ag2O and AgO interaction with glucose. The proposed non-enzymatic sensors were successfully applied for non-enzymatic amperometric detection, exhibiting a linear range from 1 to 10 mM in the first peak (+0.7 V) and a narrow range from 1 to 2 mM with higher sensitivity of 52.2 mA/mM and improved LOD of 45 μM in the second peak (+0.55 V). The applicability of the LIG/AgNPs sensor was evaluated with spiked artificial saliva in a PoC format using a smartphone potentiostat, showing an average recovery rate of 91%. The analysis was performed in a portable, mobile, and low-cost fashion using a simulated non-invasive sample, with promising results in clinical ranges.

Non-Enzymatic Electrochemical Sensing of Glucose with a Carbon Black/Polyaniline/Silver Nanoparticle Composite

“…The alcohol proton of the formed intermediated species then interacts with silver oxide, generating gluconolactone. According to the literature, the complete oxidation of glucose occurs in anodic scanning with the formation of gluconate [47]. Figure 7b demonstrates glucose oxidation by pure AgNP.…”

“…Subsequently, mediated extraction of hydrogen from the anomeric carbon of the glucose takes giving rise to the peak of high intensity close to 0.7 V [38,45,46]. The alcohol proton formed intermediated species then interacts with silver oxide, generating gluconola According to the literature, the complete oxidation of glucose occurs in anodic sca with the formation of gluconate [47]. Figure 7b demonstrates glucose oxidation by AgNP.…”

Portable glucose sensing analysis based on laser-induced graphene composite electrode

“…At present, the combination of various biosensors and intelligent devices has become a hot research direction. [53][54][55] The prepared LIG/PEDOT/Au/GOx electrode can be used for portable detection by connecting SenSit Smart U disk portable electrochemical analyzer combined with smart phone detection (Fig. 11).…”