Department of Electrical and Biomedical Engineering, University of Nevada, Reno, NV, USA; Biomedical Engineering Program, University of Nevada, Reno, NV, USA.
Department of Electrical and Biomedical Engineering, University of Nevada, Reno, NV, USA; Biomedical Engineering Program, University of Nevada, Reno, NV, USA.
J Pharm Biomed Anal. 2024 Jan 20;238:115840. doi: 10.1016/j.jpba.2023.115840. Epub 2023 Nov 4.
Recently, Mn-doped semiconductor nanocrystals (NCs) with high brightness, long lifetimes, and low-energy excitation are emerging for time-resolved luminescence biosensing/imaging. Following our previous work on Mn-doped NCs, in this work we developed poly(styrene-co-maleic anhydride) (PSMA)-encapsulated Mn-doped AgZnInS/ZnS NCs as signal transducers for immunoassay of capsular polysaccharide (CPS), a surface antigen and also a biomarker of Burkholderia pseudomallei which causes a fatal disease called melioidosis. To enhance the assay sensitivity, a surface treatment for PSMA-encapsulated NCs (NC-probes) was performed to promote the presence of carboxyl groups that help conjugate more anti-CPS antibodies to the surface of NC-probes and thus enhance bioassay signals. Meanwhile, time-resolved reading on the luminescence of NC-probes was adopted to minimize the assay background autofluorescence. Both strategies essentially enhance the assay signal-to-background ratio (or equivalently the assay sensitivity) by increasing the signal and decreasing the background, respectively. Through performing and comparing immunoassays with different NC-probes (with and without surface treatment) and different signal reading methods (time-resolved reading and non-time-resolved reading), it was proven that the immunoassay adopting surface-treated NC-probes and time-resolved reading achieved a lower limit-of-detection (LOD) than the ones adopting non-surface-treated NC-probes or non-time-resolved reading. Moreover, the achieved LOD is comparable to the LOD of immunoassay using enzyme horseradish peroxidase as a signal transducer.
最近，具有高亮度、长寿命和低能量激发的 Mn 掺杂半导体纳米晶体（NCs）在时间分辨荧光生物传感/成像中崭露头角。继我们之前关于 Mn 掺杂 NCs 的工作之后，在这项工作中，我们开发了聚（苯乙烯-共-马来酸酐）（PSMA）封装的 Mn 掺杂 AgZnInS/ZnS NCs 作为信号转导体，用于检测荚膜多糖（CPS）的免疫分析，CPS 是一种表面抗原，也是导致称为类鼻疽病的致命疾病的伯克霍尔德氏菌的生物标志物。为了提高分析灵敏度，对 PSMA 封装的 NCs（NC 探针）进行了表面处理，以促进存在羧基，帮助将更多的抗 CPS 抗体结合到 NC 探针的表面，从而增强生物分析信号。同时，采用 NC 探针的时间分辨发光读取来最小化分析背景荧光。这两种策略都通过增加信号和减少背景来提高分析信号与背景的比率（或等效地提高分析灵敏度）。通过进行和比较具有不同 NC 探针（经过和未经表面处理）和不同信号读取方法（时间分辨读取和非时间分辨读取）的免疫分析，证明采用经过表面处理的 NC 探针和时间分辨读取的免疫分析比采用未经表面处理的 NC 探针或非时间分辨读取的免疫分析具有更低的检测限（LOD）。此外，所达到的 LOD 可与使用辣根过氧化物酶作为信号转导体的免疫分析的 LOD 相媲美。
