Synergistic effect-triggered fluorescence quenching enables rapid and sensitive detection of alkaline phosphatase

• Published in: Analytica chimica acta 2023-09, Vol.1272, p.341510-341510, Article 341510
• Main Authors: Mao, Guobin, Qiu, Chunmin, Luo, Xing, Liang, Yingqi, Zhao, Liqing, Huang, Weiren, Dai, Junbiao, Ma, Yingxin
• Format: Article
• Language: English
• Subjects: ALP detection; Inner filter effect; Photo-induced electron transfer; Si dots; Synergistic quenching effect
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2023.341510

The development of biosensors mediated by synergistic quenching effect is of great significance for rapid and accurate clinical diagnosis. Hence, we prepared a cyan-emitting fluorescent Si dots for alkaline phosphatase (ALP) detection through the synergistic quenching effect of inner filter effect (IFE) and photo-induced electron transfer (PET). Si dots were prepared by microwave-assisted method, which displayed high quantum yield (28.7%), as well as good physiochemical properties, such as photo-stability, pH stability, and chemical stability. As the hydrolysate of 4-nitrophenyl phosphate disodium salt hexahydrate catalyzed by ALP, both IFE and PET of 4-nitrophenyl to Si dots were used for the turn-off mode detection of ALP. The linear relationships were established between the change of fluorescence intensity and ALP concentration in the range of 0.05 U L−1 to 5.0 U L-1, and 5.0 U L−1 to 80.0 U L−1, respectively. The detection limit was 0.01 U L−1. The synergistic quenching effect caused the turn-off mode detection to be more sensitive, and it can also be used for the accurate detection of ALP in human serum, thereby showing great anti-interference ability in complex environments. [Display omitted] •Si dots with high QY and good stability were prepared by microwave-assisted method.•A reductive-PET process from pNP to excited Si dots was firstly found.•The synergistic effect of IFE and PET provides good sensitivity for ALP detection.•The two modes of ALP detection using Si dots display high sensitivity and wide linear range.