Enhanced Near-Infrared Electrochemiluminescence from Trinary Ag–In–S to Multinary Ag–Ga–In–S Nanocrystals via Doping-in-Growth and Its Immunosensing Applications

Abstract

Screening toxic-element-free and biocompatible electrochemiluminophores was crucial for electrochemiluminescence (ECL) evolution. Herein, L-glutathione (GSH)-capped Ag−Ga−In−S (AGIS) nanocrystals (NCs) were prepared by doping Ag−In−S (AIS) NCs in a doping-in-growth way and utilized as a model for both ECL modulating and developing multinary NC-based electrochemiluminophores with enhanced ECL performance than trinary NCs. AGIS NCs not only primarily preserved the morphology, size, phase structure, and water monodisperse characteristics of AIS NCs with broadened band gap but also demonstrated obviously enhanced oxidative-reduction ECL than AIS NCs. Importantly, ECL of AGIS NCs was located at the nearinfrared region with a maximum emission wavelength of 744 nm and could be utilized for an ECL immunoassay with human prostate-specific antigen (PSA) as a model, which exhibited a linearity range from 0.05 pg/mL to 1.0 ng/mL and a low limit of detection of 0.01 pg/mL (S/N = 3). This work provided a promising alternative to the traditional binary NCs for developing toxicelement-free and biocompatible electrochemiluminophores with efficient near-infrared ECL.

Surface-Defect-Induced and Synergetic-Effect-Enhanced NIR-II Electrochemiluminescence of Au–Ag Bimetallic Nanoclusters and Its Spectral Sensing

“…The ECL response of a mixture of CA125 and all of the interfering substances was almost identical to the pure CA125 sample. It was clear the selectivity of the NIR-II ECL immunosensor was predominately determined by the specific interaction between the antibody and the antigen, similar to previously reported sandwich ECL immunosensors with NCs as tags. , …”

“…The instruments and methods used for characterization have been detailed in our previous papers. ,, Ultraviolet–visible (UV–vis) absorption spectra were measured with a TU-1901 UV–vis spectrophotometer (Beijing Purkinje General Instrument Co., Ltd., China). PL spectra were recorded with an F-320 spectrofluorimeter (Tianjin Gangdong Sci.…”

“…The GCE|ABA was then linked with Ab 1 to form GCE|ABA–Ab 1 with the assistance of EDC/NHS. GCE|ABA–Ab 1 was rinsed with PBST (where PBST is 10 mM PBS with 0.02% Tween 20) and incubated with 2% (v/v) BSA for 30 min to block any remaining activated carboxyl groups . GCE|ABA–Ab 1 was further linked with the target antigen, i.e., CA125, via dropping 20 μL of CA125 solution of different concentrations onto its surface and incubating them together for 90 min.…”

Progress in spectrum-based electrochemiluminescence quantitative analysis

“…Zn-Ag-In-S/ZnS量子 点的ECL辐射强度为三元CIS/ZnS量子点的4.2倍, 其 辐射波段位于可见光区605 nm处, 而且ECL光谱与钌 联吡啶/三丙胺体系基本一致. Fu等 [100] 发现Ag-Ga-In-S 量子点具有近红外的缺陷型单波段ECL特性, 其ECL 辐射波段位于744 nm处, 推动实现了四元量子点类 ECL物质辐射波段的调控. 三元CIS类量子点 [47,96~99] 与 四元Zn-Ag-In-S [61] 和Ag-Ga-In-S类量子点 [100] 的单波段 ECL均为缺陷辐射, 说明抑制本征辐射也可以开发新 型单波段ECL物质.…”

Near‐infrared Responsive Photoelectrochemical Biosensors

“…Near-infrared (NIR) light with wavelength over 650 nm up to 1700 nm is of increasing interest in biosensing and biomedicine owing to its capability of low spectral interference, deep tissue penetration, and minimal photodamage to biological species [31][32][33]. NIR fluorescent [34][35], bioluminescent [36], chemiluminescent [37] probes, as well as electrochemiluminescence luminophores [38][39][40] have been extensively exploited for biosensing and in situ bioimaging. More excitingly, NIR PEC sensors have begun to emerge since 2016 [41].…”