Dopamine‐loaded Liposomes‐amplified Electrochemical Immunoassay Based on MXene (Ti₃C₂)−AuNPs

Abstract

A simple and novel electrochemical immunoassay based on MXene (Ti3C2)−Au nanoparticles (AuNPs) was designed for sensitive screening of a disease‐related biomarker, prostate‐specific antigen (PSA), by using dopamine‐loaded liposomes (DLL) for signal amplification. The system involves two parts, namely, sandwich‐type immunoreaction to capture DLL and electrochemical measurement of dopamine. The target PSA can cause a specific antigen‐antibody reaction and DLL are enriched in the enzyme‐labeled pores. After Triton X‐100 is injected into the detection cell, the carried DLL was quickly cracked to release dopamine wrapped in the cavity. A nanocomposite consisting of MXene (Ti3C2) support to immobilize Au nanoparticles (Ti3C2−Au) was utilized to modify a glassy carbon electrode, which gives a strongly enhanced differential pulse voltammetric (DPV) signals for dopamine. In this case, the change of DPV signal depends on the amount of dopamine released by liposomes, which is further positively correlated with the concentration of the analyte PSA. Combining the of MXene (Ti3C2)−AuNPs nanomaterials (large specific surface area, excellent electrical conductivity, and good electrocatalytic properties) with the liposome signal amplification strategy, the electrochemical immunoassay exhibited excellent performance toward PSA determination with a broad linear range of 1 pg/mL to 50 ng/mL and limit of detection down to 0.31 pg/mL (S/N=3) under the optimized testing conditions. High specificity for PSA over other disease‐related biomarkers and acceptable nanocomposite/electrode stability were acquired. The excellent analytical performance shows that the current strategy provides an effective detection platform for clinical sample analysis.

Highly Reliable Chiral Discrimination of Tryptophan Enantiomers through Two Different Modes: Electrochemistry and Temperature

“…MXene-AuNPs was synthesized by the MXene self-reduction method. , In a typical procedure, 10 mg of the few-layered MXene was dispersed in 25 mL of water and sonicated for 20 min, and then, 2 mL of HAuCl 4 ·3H 2 O aqueous solution (25 mM) was injected slowly into the MXene suspension with continuous stirring. After self-reduction for 15 min, the AuNPs were grown in situ on the MXene, and the obtained MXene-AuNPs was centrifugally collected, washed several times with water, and freeze-dried.…”

“…As an emerging family of 2D materials, transition metal carbides/nitrides/carbonitrides called MXenes have aroused rapidly increasing attention since their discovery in 2011 by Gogotsi’s group. , Thanks to their distinguishing features such as high electrical conductivity, large specific surface area, and excellent hydrophilicity, MXenes have been widely employed in electrochemical sensing. − Particularly, the transition metal M in MXenes has a strong electron-donating ability since the oxidation number of M in MXenes is much less than that in the metal oxides, and thus, noble metal nanoparticles can be immobilized on the MXenes substrate without the assistance of external reducing agents . On the other hand, MXenes have recently emerged as one of the most promising photothermal transducers due to their outstanding photothermal conversion efficiency, , which opens the window for the design of temperature sensing platforms with MXenes.…”

“…Herein, we report on the construction of a chiral sensing platform for chiral discrimination through two different modes: electrochemistry and temperature. Since MXenes have a strong metal reduction ability without extra reducing agents and stabilizers, , Au nanoparticles (AuNPs) were grown in situ on MXene (Ti 3 C 2 T x ) nanosheets by the MXene self-reduction method. N -Acetyl- l -cysteine (NALC) could be further anchored to the MXene-AuNPs through Au–S bonds, which functioned as the chiral source for chiral discrimination .…”

Porous gold-layered cubic and octahedral Cu-oxide nanocrystals: Dopamine sensing

“…Due to the high conductivity of gold nanoparticles, they have been successfully employed for DA sensing, 26–28 using nanoporous gold structures results in an even higher electrocatalytic activity due to the increased surface area. 29,30 A gold–cuprous oxide nanocomposite resulted in a synergistic effect for the detection of DA and could differentiate it in the presence of interfering biological molecules, such as uric acid (UA) and ascorbic acid (AA).…”

Recent advances on portable photoelectrochemical biosensors for diagnostics

“…Health continues to be a hot topic for global research due to the high mortality rates of chronic and infectious diseases [42,43]. Sensitive, simple, and rapid diagnostic methods play a decisive role in the treatment of chronic diseases [44][45][46]. Early diagnosis and treatment of disease can significantly reduce mortality and human suffering [47,48].…”