Dual-Mechanism Quenching of Electrochemiluminescence Immunosensor Based on a Novel ECL Emitter Polyoxomolybdate-Zirconia for 17β-Estradiol Detection

Abstract

The exploration of novel electrochemiluminescence (ECL) reagents has been a breakthrough work in ECL immunoassay. In this work, the ECL properties of polyoxomolybdate-zirconia (POM-ZrO2) were discovered for the first time and their luminescence mechanism was initially explored. Virgulate POM-ZrO2 was synthesized from phosphomolybdic acid hydrate and zirconium oxychloride by solvothermal method, which achieved intense and stabilized cathode ECL emission at a negative potential. Polyaniline@Au nanocrystals (PANI@AuNPs) as the executor of the dual-mechanism quenching strategy were used to reduce the output signal. The quenching efficiency was significantly enhanced by the dual mechanisms of ECL energy transfer and electron transfer. Specifically, PANI@AuNPs can serve as an energy receptor to absorb the energy emitted by POM-ZrO2 (energy donor), while the appropriate energy level can be regarded as the condition for electron transfer to quench the ECL intensity of POM-ZrO2. Herein, the proposed dual-mechanism quenching strategy was applied to the immunoassay of 17β-estradiol by constructing a competitive immunosensor. As expected, the immunosensor demonstrated favorable analytical performance and a wide sensing range from 0.01 pg/mL to 200 ng/mL. Hence, it provides a novel method for the sensitive analysis of other biomolecules, such as disease markers and environmental estrogens.

Signal “On-Amplified-Off” Strategy Based on Hafnium Dioxide Nanomaterials as Electrochemiluminescence Emitters for Progesterone Detection

“…The ECL emission spectrum (Figure B) and photoluminescence (PL) spectrum (Figure C) of HfO 2 were measured, and the PL spectrum exhibited a redshift of 360 nm in comparison to the ECL emission position situated at 650 nm. This observation suggested the surface state emission of HfO 2 . The oxidation state of the HfO 2 modified electrode in different solutions was investigated.…”

“…This observation suggested the surface state emission of HfO 2 . 43 The oxidation state of the HfO 2 modified electrode in different solutions was investigated. As shown in Figure 4D, the electrochemical properties of HfO 2 were evaluated by performing differential pulse voltammetry (DPV) in PBS with and without TPrA.…”

Dual Direct Z-Scheme Heterojunction with Stable Electron Supply to a Au/PANI Photocathode for Ultrasensitive Photoelectrochemical and Electrochromic Visualization Detection of Ofloxacin in a Microfluidic Sensing Platform

“…Furthermore, the absorption peaks at 1315 cm –1 belong to the CN stretching of secondary aromatic amines. It can be seen that the peaks at 1160 cm –1 and 837 cm –1 were the C–H on the benzene ring and C–H bending vibration outside of the counterpoint double-substituted benzene ring, respectively . In addition, the SEM image in Figure C illustrates that Au was uniformly distributed on the surface of ITO.…”

“…It can be seen that the peaks at 1160 cm −1 and 837 cm −1 were the C−H on the benzene ring and C−H bending vibration outside of the counterpoint double-substituted benzene ring, respectively. 35 In addition, the SEM image in Figure 2C illustrates that Au was uniformly distributed on the surface of ITO. After electrodeposition of PANI (Figure 2D,E), Au was covered with PANI films, which further demonstrated the successful synthesis of Au/PANI.…”

Viscosity-Responsive Electrochemiluminescence of Diphenylbenzofulvene Derivatives

“…Electrochemiluminescence (ECL) is a unique luminescent phenomenon generated by electrically stimulating substances to produce a species in an excited state and finally returning them to the ground state. − Since it integrates the characteristics of both luminescence and electricity, ECL features many advantages like high sensitivity, simple operation, low inherent background, and strong controllability. Over the past decade, ECL has acted as a powerful analytical tool in numerous fields including bioimaging, immunoassays, pharmaceutical detection, clinical diagnosis, and environment and food analysis. − In particular, ECL has advanced rapidly in recent years. For example, the intriguing concept of “aggregation-induced emission” , was introduced in the ECL field, known as “AIE-ECL”, which achieved the water-insoluble organic probes for ultrasensitive aqueous-phase detection. − Furthermore, the intensity of the AIE-ECL system gives rise to a clearly distinguishable change with the aggregation degree of the emitter.…”