Ultrasound-pretreatment combined with Ti3C2-TiO2-AuNPs enhancing the electrogenerated chemiluminescence of the air-saturated luminol for exosomes detection

It is still a great challenge to develop effective strategies to improve the low electrogenerated chemiluminescence (ECL) of air-saturated luminol. Herein, the synergistic effects of Ti3C2-TiO2-AuNPs nano hybrid and high-intensity focused ultrasound pretreatment (ultrasound-pretreatment) were used to significantly improve the ECL emission of the air-saturated luminol, and the mechanism was proposed. The ultrasound-pretreatment as a green method with the cavitation effect could form O2-• and H2O2 in situ as an initiator. TiO2 and Au nanoparticles (AuNPs) were in situ decorated on the Ti3C2 surface to form Ti3C2-TiO2-AuNPs, and it was proved as a highly efficient booster which could catalyze and aggregate H2O2 to the O2-•. The utilization rate of intermediates has been greatly improved. Exosomes as model targets can be sensitively detected by the ECL sensor. The detection limit was 195 particles μL-1. The detection results of exosomes in actual samples are satisfactory. We believe that the ultrasound-pretreatment strategy could be extended to the sensitive detection in the biological sample.