Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Beibei, Chongqing, 400715, China.
Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Beibei, Chongqing, 400715, China.
Talanta. 2020 Jun 1;213:120827. doi: 10.1016/j.talanta.2020.120827. Epub 2020 Feb 12.
A novel signal amplification method for prostate specific antigen (PSA) is developed by freeing fluorescein with photoinduced oxidase-like activity from coordination nanoparticles (CNPs) in the presence of alkaline phosphatase (ALP). CNPs loaded with fluorescein (F@CNPs) are obtained in aqueous solution by self-assembly using Tb as metal ion, guanosine monophosphate (5'-GMP) as ligand, and fluorescein as signal molecule. The F@CNPs display outstanding properties of simple synthesis, low cost, good water solubility, negligible leakage and satisfactory load capacity. Fluorescein is quantitatively encapsulated in CNPs with a binding ratio of 92.72%. Meanwhile, ALP can specifically hydrolyze the phosphate group of 5'-GMP ligand, triggering the destruction of F@CNPs and leakage of fluorescein. Fluorescein, a photoinduced oxidase mimic, can catalyze the oxidation of non-fluorescent Amplex UltraRed (AUR) into fluorescent resorufin under LED lamp. This strategy exhibits good sensitivity for ALP detection. In addition, a new immunoassay for PSA is validated by labelling ALP on PSA antibody. The low detection limit of 0.04 ng mL in detecting PSA is appropriate for PSA detection in real samples. Therefore, the work not only establishes a new strategy for ALP and PSA determination, but also provides a new conception for putting photoinduced oxidase-like fluorescein in practical application.
一种用于前列腺特异性抗原（PSA）的新型信号放大方法是通过在碱性磷酸酶（ALP）存在的情况下从配位纳米粒子（CNP）中释放具有光诱导氧化酶样活性的荧光素而开发的。通过使用铽作为金属离子、单磷酸鸟苷（5'-GMP）作为配体、荧光素作为信号分子，在水溶液中通过自组装获得负载有荧光素的 F@CNP。F@CNP 具有合成简单、成本低、水溶性好、泄漏率低和载药量满意等突出性能。荧光素以 92.72%的结合比定量封装在 CNP 中。同时，ALP 可以特异性水解 5'-GMP 配体的磷酸基团，触发 F@CNP 的破坏和荧光素的泄漏。荧光素作为一种光诱导氧化酶模拟物，可以在 LED 灯下催化非荧光 Amplex UltraRed（AUR）氧化为荧光 Resorufin。该策略对 ALP 的检测具有良好的灵敏度。此外，通过在 PSA 抗体上标记 ALP，验证了用于 PSA 的新免疫测定法。在检测 PSA 时，检测限低至 0.04ng/mL，适用于实际样品中的 PSA 检测。因此，这项工作不仅建立了一种用于 ALP 和 PSA 测定的新策略，而且为将具有光诱导氧化酶样活性的荧光素实际应用提供了新概念。
