Two birds with one stone: Amine-functionalized MSNs@Eu(OH)CO3 nanoprobe for efficient dissolution-enhanced afterglow bioassay
Fuying Zhang, Donghao Hu, Xianlong Su, Zhengdao Hong, Wei Feng, Ming Xu, Fuyou Li
Abstract
The efficient detection of tumor markers is crucial to early cancer diagnosis and monitoring. Here, we propose a unique “two birds with one stone” dissolution-enhanced afterglow bioassay based on amino-functionalized mesoporous SiO2 nanoparticles (MSNs-NH2) encapsulated Eu(OH)CO3 nanoprobes. These nanoprobes (i) stably conjugate to the antibody and (ii) are highly soluble in the acidic enhancer solution, and provide a high Eu3+ concentration. The released Eu3+ ions further activate the photochemical afterglow system to determine the alpha-fetoprotein (AFP) levels in clinical serum samples. Without the use of a real-time excitation source, the interference of autofluorescence and scattering from blood can be avoided. The demonstrated limit of detection (LOD) for AFP was as low as 0.12 ng·mL−1. This covalently connected dissolution-enhanced luminescent bioassay (DELBA) and novel afterglow system shows tremendous potential for ultrasensitive and rapid clinical diagnosis.