Upconversion NaYF₄:Yb/Er–TiO₂–Ti₃C₂ Heterostructure-Based Near-Infrared Light-Driven Photoelectrochemical Biosensor for Highly Sensitive and Selective d-Serine Detection

Abstract

A near-infrared (NIR) light-driven NaYF4:Yb/Er–TiO2–Ti3C2 (NYF–TiO2–Ti3C2) heterostructure-based photoelectrochemical (PEC) biosensing platform was constructed for highly sensitive d-serine (d-ser) detection. Accurate d-ser detection depends on the model biocatalyst, d-amino acid oxidase (DAAO), which converts d-ser into hydroxypyruvate and an equimolar concentration of hydrogen peroxide (H2O2) via an enzymatic reaction. The TiO2–Ti3C2 semiconductor and NaYF4:Yb/Er optical transducer formed a Schottky junction that provided an irreversible channel for electron transfer. Infrared light was converted into absorbable multiemission light, thereby effectively increasing light absorption. Simultaneously, the generated H2O2 rapidly scavenged photogenerated holes to separate electron–hole pairs, which amplified the photocurrent signal. Under optimal conditions, the NIR light-driven PEC biosensor exhibited an excellent PEC performance for d-ser detection, with a wide linear range of 2–1650 μmol L–1 and detection limit as low as 0.286 μmol L–1. Importantly, high detection reproducibility and accuracy were achieved using this strategy for analyzing human serum and rat cerebrospinal fluid (CSF) specimens. The admirable applicability of the NYF–TiO2–Ti3C2-based PEC biosensor for detecting d-ser may lead to further opportunities for detecting other disease-related biomarkers.

Customized Synthesis of 2D Ti3C2 MXene for Improved Overall Water Splitting

“…In general, when an intercalant is introduced, more H 2 O molecules are pushed between the MXene layers, thus increasing the interlayer distance. 36,39 The Raman results reveal that the interlayer spacing was maximum in the TC40 sample and minimum in the TC20.…”

Recent advances on portable photoelectrochemical biosensors for diagnostics

“…Huang et al. constructed a near‐infrared (NIR)‐driven photoelectrochemical (PEC) biosensing platform based on the heterogeneous structure of NaYF 4 :Yb/Er‐ TiO 2 −Ti 3 C 2 (NYF−TiO 2 −Ti 3 C 2 ) [153]. The structure proved a new method for the highly sensitive detection of D‐serine (D‐ser).…”

Carbon Nitride-Based Heterojunction Photoelectrodes with Modulable Charge-Transfer Pathways toward Selective Biosensing

“…To date, various PEC sensors have been well-documented, such as bioanalysis-based and direct reactant-determinant PEC sensors. ,,– While the bioanalysis-based PEC biosensors employ biological elements (e.g., enzymes, antibodies, and nucleic acids) for highly specific recognition, ,– the direct reactant-determinant PEC sensors are a straightforward approach on the basis of redox reactions between the analytes and excited carriers of the photovoltaic materials. – Nonetheless, direct reactant-determinant PEC sensors receive relatively less attention owing to poor selectivity . In principle, regulating charge-transfer pathways would tune the redox reactions, which generate diverse and even opposite photocurrent changes in response to analytes, thus offering an intriguing way to improve the detection selectivity. , Interestingly, task-specific charge-transfer pathways could be modulated by orderly assembling different photovoltaic materials with suitable CB and VB positions, e.g., through the Z-scheme and Type II heterostructures (Figure d,e). ,– From the perspective of signal transduction, except for conventional endeavors in improving PEC efficiency for more sensitive detection, engineering charge-transfer pathways would play an essential role in selective PEC sensing, but to the best of our knowledge, it has been rarely reported …”