There has been increasing interest in the use of biosensors for diagnosis of infectious diseases such as tuberculosis (TB) due to their simplicity, affordability, and potential for point-of-care application. The incorporation of aptamer molecules and nanomaterials in biosensor fabrication explores the advantages of high-binding affinity and low immunogenicity of aptamers as well as the high surface-to-volume ratio of nanomaterials, for increased aptasensor performance. In this work, we employed a novel microwave-synthesized copper indium tin sulfide (CITS) substituted-kesterite nanomaterial, together with a natural biopolymer (chitosan), for signal amplification and increased loading of aptamer molecules. Study of the optical properties of CITS nanomaterials showed strong absorption in the UV region characteristic of kesterite semiconductor nanomaterials. X-ray diffraction analysis confirmed the presence of the kesterite phase with average crystallite size of 6.188 nm. Fabrication of interferon-gamma (IFN-γ) TB aptasensor with a chitosan-CITS nanocomposite (χtCITS) increased the aptasensor's electrochemical properties by 77.5 % and improved aptamer loading by 73.7 %. The aptasensor showed excellent sensitivity to IFN-γ concentrations with limit of detection of 6885 fg/mL (405 fM) and linear range of 850–17000 fg/mL (50 – 1000 fM). The aptasensor also exhibited excellent storage and electrochemical stability, with good selectivity towards IFN-γ and possible real sample application.

中文翻译：

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基于新型壳聚糖-铟纳米黄锡矿（χtCITS）标记的DNA适体发夹技术的干扰素γ（IFN-γ）敏感结核病适体传感器

由于生物传感器简单、经济实惠且具有即时护理应用的潜力，人们对使用生物传感器诊断结核病 (TB) 等传染病越来越感兴趣。将适体分子和纳米材料结合到生物传感器制造中，探索了适体的高结合亲和力和低免疫原性以及纳米材料的高表面积与体积比的优势，以提高适体传感器的性能。在这项工作中，我们采用了一种新型微波合成的铜铟锡硫化物（CITS）取代的锌黄锡矿纳米材料，以及天然生物聚合物（壳聚糖），用于信号放大和增加适体分子的负载。 CITS纳米材料的光学性质研究表明，黄锡黄锡矿半导体纳米材料在紫外区具有强吸收特性。 X 射线衍射分析证实存在平均晶粒尺寸为 6.188 nm 的黄锌矿相。使用壳聚糖-CITS 纳米复合材料 (χtCITS) 制造干扰素-γ (IFN-γ) TB 适体传感器，使适体传感器的电化学性能提高了 77.5%，适体负载量提高了 73.7%。适体传感器对 IFN-γ 浓度表现出优异的灵敏度，检测限为 6885 fg/mL (405 fM)，线性范围为 850–17000 fg/mL (50 – 1000 fM)。该适体传感器还表现出优异的储存和电化学稳定性，对 IFN-γ 具有良好的选择性，并可能用于实际样品应用。