基于适配体和SERS技术的侵袭性烟曲霉菌感染早期诊断新方法的研究

Invasive Aspergillus fumigatus infection is a serious opportunistic infection, which is caused by Aspergillus fumigatus. It always occurs in immunocompromised individuals and has a high morbidity and mortality. Infected patients always lack specific clinical manifestations, however, the commonly used detection methods at present are time-consuming with high miss rate and low sensitivity, and thus cannot meet the needs of early diagnosis of invasive Aspergillus fumigatus infection already.. Previously, aptamer screening and optimization platform has been successfully established by our group. Using aptamer as a specific biological recognition molecule, we developed biosensors with a detection limit of up to the ppt level. The two related researches have both been published in the journal Biosens Bioelectron (IF: 7.476). Therefore, our group plans to obtain aptamers that bind to Aspergillus fumigatus with high affinity and specificity through this platform, and further improve their performance through mutation, truncation, capping and other optimization strategies. By combining the aptamer with surface-enhanced Raman scattering (SERS) and introducing Raman signal molecules, a SERS-based aptasensor is to be developed for the sensitive, specific and rapid detection of Aspergillus fumigatus, which provides an effective tool for the early diagnosis and dynamic monitoring of Invasive Aspergillus fumigatus infection.

侵袭性烟曲霉菌感染是由烟曲霉菌引起的一种严重的机会性感染，好发于免疫缺陷患者，发病率和病死率均较高。感染患者往往缺乏特征性的临床表现，而常用的检测方法由于耗时长、漏检率高、灵敏度低等问题，已无法满足临床早期诊断的需求。. 本课题组前期已成功建立适配体筛选和优化平台，并将适配体作为一种特异的生物识别分子，构建的传感器检测限达到ppt级别，相关的两项研究成果均发表于期刊Biosens Bioelectron (IF:7.476)。因此，本研究拟通过该平台筛选获得与烟曲霉菌特异性结合的高亲和力适配体；通过突变、截短、加帽等优化策略进一步改善其性能；通过将适配体与表面增强拉曼光谱（SERS）技术联用，整合拉曼信号分子，构建一种基于SERS技术的适配体传感器，以实现对烟曲霉菌灵敏、特异、快速的检测，为侵袭性烟曲霉菌感染的早期诊断和动态监测提供有效工具。

侵袭性烟曲霉菌感染是由烟曲霉菌引起的一种严重的机会性感染，好发于免疫缺陷患者，发病率和病死率均较高。感染患者往往缺乏特征性的临床表现，而常用的检测方法由于耗时长、漏检率高、灵敏度低等问题，已无法满足临床早期诊断的需求。胶霉毒素是烟曲霉菌特征性的生物标志物，是其生长过程中产生的毒性最强的早期代谢产物。通过对感染患者血清或尿液样品中胶霉毒素的检测，将为侵袭性烟曲霉菌感染的早期诊断提供可能。然而，现有的检测方法，如高效液相色谱、薄层色谱等由于耗时长、样品前制备繁琐等问题，使其一直无法成为临床早期快速诊断的理想选择。同时，胶霉毒素是一个非蛋白结构的小分子真菌毒素，其产生识别配体的能力甚微，从而进一步限制了相应检测方法的发展。. 鉴于此，在本项目研究中：（1）本团队通过免固化的GO-SELEX技术筛选，获得了与胶霉毒素特异性结合的高亲和力核酸适配体；（2）通过序列截短、定点突变等多种优化策略的组合应用，进一步获得了该核酸适配体的核心序列，并显著改善了其结合亲和力、靶向特异性和结构稳定性等；（3）将核酸适配体作为分子识别工具，本团队成功构建了一种基于荧光标记核酸适配体结构转换的快速检测新方法。该方法对胶霉毒素不仅具有较高的灵敏度和特异性，而且对血清和尿液中加标的样品具有较高的回收率、较低的变异系数和较好的准确性。因此，本研究所构建的检测新方法，通过对生物标志物胶霉毒素进行灵敏、特异和快速的检测，继而为侵袭性烟曲霉菌感染的早期快速诊断提供了有效工具。