Ultrasensitive Electrochemiluminescent Sensor for MicroRNA with Multinary Zn–Ag–In–S/ZnS Nanocrystals as Tags

Abstract

For the screening of novel toxic-element-free and biocompatible electrochemiluminophores, electrochemiluminescence (ECL) of multinary nanocrystals (NCs) was investigated for the first time with Zn−Ag−In−S (ZAIS) NCs as model. Aqueous soluble ZAIS NCs could bring out efficient reductive-oxidation ECL with tri-n-propylamine as coreactant, while coating the ZAIS NCs with a ZnS shell could reduce the surface defects of ZAIS NCs, and enable 6.7-fold enhanced ECL of ZAIS/ZnS NCs as compared to ZAIS NCs. ECL of ZAIS/ZnS NCs was about 4.2-fold that of ternary CuInS 2 /ZnS NCs, spectrally similar to that of Ru(bpy) 3 2+ with maximum emission around 605 nm, and favorable for less electrochemical interference with a lowered triggering potential (∼0.95 V) than that of Ru(bpy) 32+ . An ultrasensitive ECL microRNA sensor was fabricated with ZAIS/ZnS NCs as tags, which could sensitively and selectively determine microRNA-141 with a wide linearity range from 0.1 fmol/L to 20 pmol/L and a low limit of detection at 50 amol/L (S/N = 3). Multinary NCs might provide a promising alternative to the traditional binary NCs for both electrochemiluminophore screening and NC ECL modulating.

Carbon Nanomaze for Biomolecular Detection with Zeptomolar Sensitivity

“…Conventional approaches for miRNA detection such as classic northern blotting, [ 3 ] polymerase chain reaction (PCR), [ 4 ] and microarrays [ 5 ] clearly suffer from several limitations, such as tedious procedures, complex instrumentation, and low sensitivity. Several recently developed and highly sensitive platforms integrating surface‐enhanced Raman scattering, [ 6 ] fluorescence, [ 7 ] electrochemiluminescence, [ 8 ] or electrochemical methods [ 9 ] partially overcome the abovementioned drawbacks and improve the sensitivity to approximately the 10 attomolar level. Among these approaches, electrochemical methods are the most affordable candidate, permitting ultrasensitive recognition of trace bioactive molecules with extremely low background signals.…”

Liquid Phase Interfacial Surface-Enhanced Raman Scattering Platform for Ratiometric Detection of MicroRNA 155

“…MicroRNAs (miRNAs), containing approximately 18–25 nucleotides of single noncoding RNAs, are confirmed as a kind of potential biomarker for cancer diagnosis and neurological disorders. , Compared with other detection methods, such as electrochemistry, electrochemiluminescence, and fluorescence spectroscopy, surface-enhanced Raman scattering (SERS) has unique advantages in detection of miRNAs due to its satisfactory property of high sensitivity, defect-free detection, simple operation, a unique Raman vibrational fingerprint peak, , etc. However, traditional SERS substrates often rely on noble metal nanoparticles with a surface plasmon resonance (SPR) effect on a solid substrate like a silicon wafer and ITO electrode, showing non-negligible flaws, including high steric hindrance, adsorption heterogeneity of targets, and poor reproducibility .…”

Progress in spectrum-based electrochemiluminescence quantitative analysis

“…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.…”