An ultrasensitive CH3NH3PbBr3 quantum dots@SiO2-based electrochemiluminescence sensing platform using an organic electrolyte for aflatoxin B1 detection in corn oil.

Mycotoxins contamination, especially aflatoxin B1 (AFB1) in edible oils, is a health hazard. Therefore, AFB1 trace analysis methods are urgently needed. Electrochemiluminescence (ECL) is a popular sensing method because of its low background interference and high sensitivity. However, existing ECL assays for AFB1 detection are based on aqueous rather than oil systems. Herein, we report a CH3NH3PbBr3 quantum dots (MAPB QDs)@SiO2-based ECL sensor for AFB1 quantification in corn oil using an organic electrolyte. The luminophore loading and stability of the MAPB QDs@SiO2 particles were significantly improved compared to those of bulky MAPB materials, resulting in an enhanced ECL response. Further, exploiting molecular imprinting technology, an ECL sensor for AFB1 detection with an ultra-low detection limit of 8.5 fg/mL was prepared. The reliability of the sensor was confirmed by comparable recoveries of corn oil samples with those obtained by high-performance liquid chromatography, indicating its potential for food safety evaluation.

Ultrasensitive Cytosensor Based on Self-Enhanced Electrochemiluminescent Ruthenium-Silica Composite Nanoparticles for Efficient Drug Screening with Cell Apoptosis Monitoring.

The self-enhanced electrochemiluminescence (ECL) with high sensitivity could be an effective method for anticancer drug screening with cell apoptosis monitoring. Here we reported an ultrasensitive ECL cytosensor for cell apoptosis monitoring by using self-enhanced electrochemiluminescent ruthenium-silica composite nanoparticles (Ru-N-SiNPs) labeled annexin V as signal probes. The Ru-N-SiNPs were first synthesized through simple hydrolysis of a novel precursor containing luminescent and intracoreactant groups in one molecule, which presented higher emission efficiency and enhanced ECL intensity due to the shorter electron-transfer path and less energy loss. Moreover, the as-proposed ECL cytosensor was successfully used to investigate efficiency of paclitaxel toward MDA-MB-231 breast cancer cell in the range from 1 nM to 200 nM with a detection limit of 0.3 nM and a correlation coefficient of 0.9917. The improved accuracy and excellent dynamic range revealed the potential applications in biomolecules diagnostics and cells detections, especially in living and complex systems.