In Situ Growth Intercalation Structure MXene@Anatase/Rutile TiO2 Ternary Heterojunction with Excellent Phosphoprotein Detection in Sweat

Abstract

Abnormal protein phosphorylation may relate to diseases such as Alzheimer’s, schizophrenia, and Parkinson’s. Therefore, the real-time detection of phosphoproteins in sweat was of great significance for the early knowledge, detection, and treatment of neurological diseases. In this work, anatase/rutile TiO2 was in situ grown on the MXene surface to constructing the intercalation structure MXene@anatase/rutile TiO2 ternary heterostructure as a sensing platform for detecting phosphoprotein in sweat. Here, the intercalation structure of MXene acted as electron and diffusion channels for phosphoproteins. The in situ grown anatase/rutile TiO2 with n-n-type heterostructure provided specific adsorption sites for the phosphoproteins. The determination of phosphoprotein covered concentrations in sweat, with linear range from 0.01 to 1 mg/mL, along with a low LOD of 1.52 μM. It is worth noting that, since the macromolecular phosphoprotein was adsorbed on the surface of the material, the electrochemical signal gradually decreased with the increase of phosphoprotein concentration. In addition, the active sites in the MXene@anatase/rutile TiO2 ternary heterojunction and synergistic effect of the heterojunction were verified by first-principle calculations to further realize the response to phosphoproteins. Additionally, the effective diffusion capacity and mobility of phosphoprotein molecules in the ternary heterojunction structure were studied by molecular dynamics simulation. Furthermore, the constructed sensing platform showed high selectivity, repeatability, reproducibility, and stability, and this newly developed sensor can detect for phosphoprotein in actual sweat samples. This satisfactory sensing strategy could be promoted to realize the noninvasive and continuous detection of sweat.

Recent Advances in Two-Dimensional MXene-Based Electrochemical Biosensors for Sweat Analysis

“…Qiao et al developed a Ti3C2 MXene@TiO2 (anatase/rutile) ternary heterostructured electrode to detect phosphoprotein in sweat. They showed a LOD of 1.52 µM with a broad linear range from 0.01 to 1 mg/mL [191]. Chen et al developed a [74].…”

“…Qiao et al developed a Ti 3 C 2 MXene@TiO 2 (anatase/rutile) ternary heterostructured electrode to detect phosphoprotein in sweat. They showed a LOD of 1.52 μM with a broad linear range from 0.01 to 1 mg/mL [ 191 ]. Chen et al developed a fluoroalkyl functionalized F–Ti 3 C 2 T x /polyaniline (PANI) superhydrophobic skin-attachable and wearable electrochemical pH biosensor for real-time perspiration analysis [ 192 ].…”

Special Issue “Synthetic Biology for Biosensing in Health and Environmental Applications”

“…The results suggest that the platform could be used to screen cTnI in blood serum samples. In another paper in this Special Issue, Qiao et al tackled the problem of detecting phosphoproteins in sweat for the early detection of various neurological diseases [2]. The paper examined a sensing platform for detecting phosphoprotein in sweat using an intercalation structure MXene@anatase/rutile TiO 2 ternary heterojunction.…”