Development of a Fluorescent Immunochromatographic Assay Based on Quantum Dot-Functionalized Two-Dimensional Monolayer Ti₃C₂ MXene Nanoprobes for the Simultaneous Detection of Influenza A Virus and SARS-CoV-2

Abstract

Accurate and rapid detection of the influenza A virus (FluA) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can effectively control their spread. We developed a colorimetric and fluorescent dual-functional two-channel immunochromatographic assay (ICA) biosensor to simultaneously detect the above-mentioned viruses. A unique two-dimensional Ti 3 C 2 -QD immunoprobe was established by adsorbing dense quantum dots (QDs) onto the light green monostromatic Ti 3 C 2 MXene surface, resulting in light green colorimetric and superior fluorescence signals and guaranteeing high sensitivity, stability, and excellent liquidity for ICA detection. Rapid visual screening for FluA and SARS-CoV-2 infections was applicable via a green colorimetric signal. Sensitive and quantitative detection of viruses in their early stages of infection was performed by using the fluorescence signal. Our proposed Ti 3 C 2 -QD-ICA biosensor can simultaneously detect 1 ng/mL or 2.4 pg/ mL FluA and 1 ng/mL or 6.2 pg/mL SARS-CoV-2 via its colorimetric or fluorescence signals, respectively, with a short testing time (20 min), good reproducibility, specificity, and accuracy. In addition, this method demonstrated sensitivity higher than that of the conventional AuNP-based ICA method in throat swab samples. Hence, our proposed Ti 3 C 2 -QD-ICA method can be potentially applied for the rapid, ultrasensitive, and multiplex detection of respiratory viruses.

Recent advances using MXenes in biomedical applications

“…Optical sensing applications with MXenes, began with colorimetric, 156,157 fluorescent, 156,[158][159][160][161][162][163][164] chemiluminescence (ECL), [165][166][167][168][169][170][171] and surface plasmon resonance (SPR) detection [172][173][174][175][176][177] and are summarized in Table 3; in recent years, photoelectrochemical (PEC) detection [178][179][180][181][182][183][184][185][186] and surfaceenhanced Raman scattering (SERS) detection have been added. 159,[187][188][189] Their metallic conductivity, rich surface chemistry, hydrophilicity, good biocompatibility, and high anchoring capacity for biomaterials make them an attractive candidate for detecting a variety of analytes.…”

Recent Advances in Lateral Flow Assays for Viral Protein Detection with Nanomaterial-Based Optical Sensors

“…Liu et al developed a colorimetric and fluorescent dual-functional LFA strip that introduced MXene and QDs to simultaneously detect IAV and SARS-CoV-2, which are difficult to distinguish due to their similar symptoms. High-sensitivity multiple detection of 1 ng/mL or 2.4 pg/mL IAV and 1 ng/mL or 6.2 pg/mL SARS-CoV-2 can be completed within 20 min [84]. Liang et al prepared Ag NPs with ultrathin Au shells (~2 nm) embedded with MBA (Ag MBA @Au) and incorporated them into LFAs for colorimetric and SERS bimodal detection of SARS-CoV-2 IgG.…”

Multi-MXene assisted large-scale manufacturing of electrochemical biosensors based on enzyme-nanoflower enhanced electrodes for the detection of H2O2 secreted from live cancer cells

“…, graphene and Au/Pt/Ag), the abundant surface functional groups (–O, –OH and –F) on MXene nanosheets allow them to be easily dispersed in an aqueous system, revealing their high practicability in water-based ink systems. 23,24 Moreover, its excellent electrical conductivity (∼24 000 S cm −1 ) 25 supports the fast direct electron transfer from the redox center to the bare electrode, which is conducive to enhancing the sensitivity of biosensors for electrochemical detection. However, the single or few layers of MXene (s-MXene) nanosheets dispersed in the supernatant were collected and applied in biosensors.…”