Elucidating mechanisms and DFT analysis of monometallic Vanadium incorporated nanoporous TiO2 as advanced material for enzyme-free electrochemical blood glucose biosensors with exceptional performance tailored for point-of-care applications

Abstract

Diabetes is a chronic condition that can last a lifetime and has claimed a great number of lives in recent years. This motivated scientists to design a glucose biosensor to monitor and control blood glucose levels in diabetic patients. Herein, hydrothermal derived Vanadium (V), Nickel (Ni), and Cobalt (Co)-doped TiO<inf>2</inf> (M<inf>x</inf>Ti<inf>1-x</inf>O<inf>2</inf> (x = 0.01, 0.02, and 0.03)) was synthesized to achieve the best material to answer the pertaining problem. Of all the materials synthesized, V<inf>0.03</inf>Ti<inf>0.97</inf>O<inf>2</inf>@NF demonstrated the highest level of sensitivity, and selectivity, and has higher electrochemical cycling stability in 0.1 M KOH. It exhibits a very high sensitivity of 1129.31 μAmM-1cm-2 and Limits of Detection (LOD) and Limits of Quantification (LOQ) of 1.8 μM (S/N = 3) and 6.2 μM, respectively, with a broad linear range from 20 μM to 2 mM. The DFT approach was employed computationally to analyze the adsorption of glucose on surfaces of pure TiO<inf>2</inf> and TiO<inf>2</inf> doped with V, Ni, and Co respectively. The research findings highlight that when it comes to its interaction with glucose, pure TiO<inf>2</inf> exhibits significantly less reactivity compared to transition metal-doped TiO<inf>2</inf>. Experimentally it shows that the V<inf>0.03</inf>Ti<inf>0.97</inf>O<inf>2</inf>@NF surface has the most sensitive glucose detection capability and it also exhibited significant selectivity towards glucose in the presence of additional interference. It demonstrated 100% retention after cycling stability and had a shelf life of ≃30 days. The V<inf>0.03</inf>Ti<inf>0.97</inf>O<inf>2</inf>@NF-based sensor exhibits accurate glucose sensing, even for human serum samples. © 2024 Elsevier B.V.