An electrochemical sensing methodology using an insect odorant receptor (iOR) as the biological recognition element for detection of odorant compounds is presented. Or22a from the fruit fly Drosophila melanogaster (DmOr22a) was used as a model receptor for the study. DmOr22a in phospholipid nanodisc preparations was shown to be functionally active toward its known ligand (ethyl hexanoate), as measured by electrochemical impedance spectroscopy (EIS). iOR nanodiscs covalently immobilized on a gold substrate were further characterized by atomic force microscopy (AFM), quartz crystal microbalance with dissipation monitoring (QCM-D) and neutron reflectometry in order to study surface modification and understand the underlying mechanisms associated with ligand binding. The EIS sensor exhibited high sensitivity and specificity towards ethyl hexanoate with a detection limit of 5.5 fM. Neutron reflectometry studies provided evidence to support conformational changes in the receptor upon ligand binding. The EIS based detection strategy provides a facile, sensitive and fast method for detecting odorant compounds and paves the way for further development of odorant biosensors.

提出了一种使用昆虫气味受体（iOR）作为生物识别元件检测气味化合物的电化学传感方法。果蝇果蝇Or22a（DmOr22a）被用作研究的模型受体。通过电化学阻抗谱（EIS）测量，磷脂纳米圆盘制剂中的DmOr22a对已知的配体（己酸乙酯）具有功能活性。通过原子力显微镜（AFM），带耗散监测的石英晶体微天平（QCM-D）和中子反射法进一步表征了共价固定在金基底上的iOR纳米圆盘，以研究表面修饰并了解与配体结合相关的潜在机理。EIS传感器对己酸乙酯具有很高的灵敏度和特异性，检测极限为5.5 fM。中子反射法研究提供了证据，以支持配体结合后受体的构象变化。基于EIS的检测策略提供了一种简便，