最近,开发了各种基于气味结合蛋白(OBP)的生物传感器,用于检测气味和信息素。然而,关于各种碳数醛的灵敏和选择性检测,存在重要的数据空白。在这项工作中,一种基于OBP2a的电化学阻抗谱(EIS)生物传感器是通过将OBP2a固定在金叉指电极上而开发的,并通过EIS和原子力显微镜进行表征。EIS反应显示基于OBP2a的生物传感器对香茅醛高度敏感,百合醛,octanal,和癸醛(检出限为10-11mol/L),与小分子醇和脂肪酸等干扰气味剂相比,对醛具有选择性(选择性系数低于0.15)。此外,基于OBP2a的生物传感器具有很高的重复性(相对标准偏差:1.6%-9.1%,每种气味剂n=3),稳定性(NIC在第6天下降了3.6%),和回收率(三个实际样品为91.2%-96.6%)。更具体地说,生物传感器对醛的敏感性与气味剂的分子量和杂环分子结构呈正相关。这些结果证明了基于OBP2a的EIS生物传感器的可用性和潜在用途,用于在医学诊断等方面快速和灵敏地检测醛。食物和青睐分析,和环境监测。
Recently, various biosensors based on odorant-binding proteins (OBPs) were developed for the detection of odorants and pheromones. However, important data gaps exist regarding the sensitive and selective detection of
aldehydes with various carbon numbers. In this work, an OBP2a-based electrochemical impedance spectroscopy (EIS) biosensor was developed by immobilizing OBP2a on a gold interdigital electrode, and was characterized by EIS and atomic force microscopy. EIS responses showed the OBP2a-based biosensor was highly sensitive to citronellal, lily aldehyde, octanal, and decanal (detection limit of 10-11 mol/L), and was selective towards
aldehydes compared with interfering odorants such as small-molecule alcohols and fatty acids (selectivity coefficients lower than 0.15). Moreover, the OBP2a-based biosensor exhibited high repeatability (relative standard deviation: 1.6%-9.1 %, n = 3 for each odorant), stability (NIC declined by 3.6 % on 6th day), and recovery (91.2%-96.6 % on three real samples). More specifically, the sensitivity of the biosensor to
aldehydes was positively correlated to the molecular weight and the heterocyclic molecule structure of the odorants. These results proved the availability and the potential usage of the OBP2a-based EIS biosensor for the rapid and sensitive detection of
aldehydes in aspects such as medical diagnostics, food and favor analysis, and environmental monitoring.