Field-effect transistor (FET) biosensors based on low-dimensional materials are capable of highly sensitive and specific label-free detection of various analytes. In this work, a FET biosensor based on graphene decorated with gold nanoparticles (Au NPs) was fabricated for lactose detection in a liquid-gate measurement configuration. This graphene device is functionalized with a carbohydrate recognition domain (CRD) of the human galectin-3 (hGal-3) protein to detect the presence of lactose from the donor effect of lectin – glycan affinity binding on the graphene. Although the detection of lactose is important because of its ubiquitous presence in food and for disease related applications (lactose intolerance condition), in this work we exploit the lectin/carbohydrate interaction to develop a device that in principle could specifically detect very low concentrations of any carbohydrate. The biosensor achieved an effective response to lactose concentrations over a dynamic range from 1 fM to 1 pM (10⁻¹⁵ to 10⁻¹² mol L⁻¹) with a detection limit of 200 aM, a significant enhancement over previous electrochemical graphene devices. The FET sensor response is also specific to lactose at aM concentrations, indicating the potential of a combined lectin and graphene FET (G-FET) sensor to detect carbohydrates at high sensitivity and specificity for disease diagnosis.

基于低维材料的场效应晶体管（FET）生物传感器能够对各种分析物进行高度灵敏且无标记的检测。在这项工作中，制造了一种基于石墨烯的FET生物传感器，该石墨烯装饰有金纳米颗粒（Au NPs），用于液门测量配置中的乳糖检测。该石墨烯装置可通过人半乳凝素3（hGal-3）蛋白的碳水化合物识别域（CRD）进行功能化，以通过凝集素的供体作用检测乳糖的存在-聚糖对石墨烯的亲和力结合。尽管乳糖的检测很重要，因为它在食品中普遍存在并且对于疾病相关的应用（乳糖不耐症），在这项工作中，我们利用凝集素/碳水化合物相互作用来开发一种设备，该设备原则上可以特异性地检测非常低浓度的任何碳水化合物。该生物传感器在1 fM至1 pM的动态范围内实现了对乳糖浓度的有效响应（10^-15至10 ^-12  mol L ^-1），检测极限为200 aM，与以前的电化学石墨烯器件相比有显着提高。FET传感器的响应也对aM浓度的乳糖具有特异性，表明凝集素和石墨烯FET（G-FET）组合传感器在疾病诊断中以高灵敏度和特异性检测碳水化合物的潜力。