A sandwich electrochemiluminescent assay for determination of concanavalin A with triple signal amplification based on MoS2NF@MWCNTs modified electrode and Zn-MOF encapsulated luminol

Electrochemiluminescent assay based on Co-MOF and TiO2 for determination of bisphenol A

An electrochemiluminescence (ECL) sensor for determining bisphenol A (BPA) was prepared based on titanium dioxide (TiO2) and Co-MOF. TiO2 is a co-reaction promoter that amplifies the ECL signal in the Ru(bpy)32+-trinpropylamine (TPrA) system. When the electrode is modified with Co-MOF the ECL signal is significantly enhanced. This is because Co-MOF can not only be used as a co-reaction accelerator but also as a carrier to adsorb more luminescent substances. Possible mechanisms for amplifying the original signal through the synergistic action of the two substances are investigated. The ECL strength decreases with increasing concentrations of BPA, and the amount of BPA can be determined by the change in ECL signal strength (ΔI). Under optimal experimental conditions, the linear range of BPA was 2.0 × 10-10 to 2.0 × 10-5 M, with a determination limit of 6.7 × 10-11 M (3σ/m). The relative standard deviation (RSD) of the signal for ten consecutive measurements was 1.5%. The sensor can be used to detect BPA in bottled samples with recoveries of 96 to 105%.

Versatile MXene composite probe-mediated homogeneous electrochemiluminescence biosensor with integrated signal transduction and near-infrared modulation strategy for concanavalin A detection

Based on the highly specific interaction between concanavalin A (Con A) and glucose (Glu), a competitive electrochemiluminescence (ECL) biosensor was constructed for ultrasensitive detection of Con A. Nanocomposites with excellent electrocatalytic and photothermal properties were obtained by covalently bonding zinc oxide quantum dots (ZnO QDs) to vanadium carbide MXene (V2C MXene) surfaces. The modification of ZnO QDs hinders the aggregation of V2C MXene and increases the catalytic activity of oxygen reduction reaction, thus amplifying the luminol cathodic emission. In addition, the excellent photothermal performance of the V2C MXene-ZnO QDs can convert light energy into heat energy under the irradiation of 808 nm near infrared laser, thus increasing the temperature of the reaction system and accelerating the electron transfer process to realize the synergistic amplified homogeneous ECL system. This innovative work not only enriches the fundamental research on multifunctional MXene nanomaterials for biosensing, but also provides an effective strategy for ECL signal amplification.

An enhanced chemiluminescence hybrids of luminol by sulfonated polyaniline decorated copper-based metal organic frame composite applicable to the measurement of hydrogen peroxide in a wide pH range

Here, sulfonated polyaniline (SPAN) was decorated on the surface of copper-based metal organic frame (HKUST-1) and the composite was functionalized by luminol to construct a chemiluminescence (CL) hybrids (SPAN/HKUST-1@Luminol). The as-prepared SPAN/HKUST-1@Luminol demonstrated a great dispersion and stability performance in aqueous solution. Moreover, the resultant SPAN/HKUST-1@Luminol hybrids exhibited extremely strong CL properties, and the CL quantum yield was 136 times higher than that of luminol. In particular, it exhibited outstanding CL activity not only under alkaline conditions, but also under neutral conditions. The sensitive response of the hybrid to hydrogen peroxide was used to construct CL methods for the detection of hydrogen peroxide at a wide range of pH, with the detection limit of 60 nM at a neutral condition and 25 pM at alkaline condition. Due to strong and stable signal of the SPAN/HKUST-1@Luminol, the CL method provides a viable tool for determination of H₂O₂ in biological systems and enabled the monitoring of stimulated production of H₂O₂ released by living cells.

Electrochemiluminescence from a biocatalysis accelerated N-(aminobutyl)-N-(ethylisoluminol)/dissolved O2 system for microRNA detection

A kind of biocatalyst, laccase, has been employed as a biocompatible coreactant accelerator to efficiently catalyze coreactant (dissolved O₂) for generating high local concentration of superoxide radical (O₂^•-), acquiring high-intense electrochemiluminescence (ECL) emission of ABEI (N-(aminobutyl)-N-(ethylisoluminol))/dissolved O₂ system. Furthermore, a modified strand displacement reaction with excellent amplification efficiency was constructed by replacing traditional single strand DNA to the hairpin DNA as template for triggering the immobilization of more signal probes. As a result, the biosensor for microRNA-21 determination has preeminent selectivity and favorable sensitivity with detection limit down to 80.8 aM. Significantly, the devised strategy has blazed a new path for seeking more coreaction accelerators with splendid biocompatibility thus promoting the application of ternary ECL systems in biological analysis and clinical diagnosis.