1T‐Phase WS₂ Protein‐Based Biosensor

Abstract

Metallic 1T‐phase transition metal dichalcogenides have been recognized for their desirable properties like high surface‐to‐volume ratio, high conductivity, and capacitive behavior, making them outstanding for catalytic and sensing applications. Herein, a hydrogen peroxide (H2O2) biosensor is constructed by the immobilization of hemoglobin (Hb) on 1T‐phase WS2 (1T‐WS2) sheets, and entrapment by glutaraldehyde. 1T‐WS2 not only displays electrocatalytic activity toward the reduction of H2O2 but also provides a high surface‐to‐volume ratio and conductive platform for the immobilization of Hb and facilitation of its electron transfer to the electrode surface. The advantageous role of 1T‐phase WS2 is further demonstrated for the construction of a heme‐based H2O2 biosensor compared to its 1T‐phase MoS2, MoSe2, and WSe2 counterparts. Synergistic interactions between 1T‐WS2 and Hb result in a H2O2 biosensor with high analytical performance in terms of wide range, sensitivity, selectivity, reproducibility, repeatability, and stability. These findings have profound impact in the research fields of electrochemical sensing and biodiagnostics.

Composites of Proteins and 2D Nanomaterials

“…However, unlike graphene‐based nanomaterials, TMDC sheets do not commonly utilize hydrogen bonding . Moreover, pristine TMDC nanosheets do not possess hydrophilic functional groups like graphene derivatives, which can form hydrogen bonds with proteins, but, it is possible to generate these hydrophilic groups by introducing edge defects to the TMDC sheets . Similar to graphene, hydrophobic interactions occur between the hexagonal lattice of TMDCs and the hydrophobic/aromatic functional groups of specific amino acids (alanine, valine, isoleucine, leucine, methionine, phenylalanine, tyrosine tryptophan) ( Figure a) .…”

“…d) Schematic illustration of the fabrication procedure of the hydrogen peroxide detector composed of tungsten disulfide (WS 2 ), hemoglobin (Hb), and glutaraldehyde (GTA). Reproduced with permission . Copyright 2017, Wiley‐VCH.…”

“…Antibody proteins can also be physisorbed on TMDCs via hydrophobic interactions . These TMDCs labeled with biomarkers can act as active material on field‐effect transistors (FETs) in chemical or biological sensors . For example, MoS 2 ‐based FETs decorated with antibody proteins designed to connect to prostate antigens, were used to detect and monitor prostate cancer (Figure c) .…”

“…In addition, nonspecific binding interactions are minimized due to specific binding facilitated by antibody and antigen proteins . Charge interactions between proteins and TMDCs are used to exfoliate TMDCs and to assemble functional nanocomposites for sensing and photothermal treatments . For example, metallic phase of 1T WS 2 can interact electrostatically with hemoglobin to generate nanocomposite platforms for electrochemical peroxide sensing (Figure d) .…”

“…Charge interactions between proteins and TMDCs are used to exfoliate TMDCs and to assemble functional nanocomposites for sensing and photothermal treatments . For example, metallic phase of 1T WS 2 can interact electrostatically with hemoglobin to generate nanocomposite platforms for electrochemical peroxide sensing (Figure d) . The proteins remain unbound to WS 2 layers and it is stabilized through cross‐linking with glutaraldehyde to restrict electrochemical activity at the interface of WS 2 and hemoglobin (Figure d) .…”