Dipartimento di Chimica, Università degli Studi di Bari "Aldo Moro", 70125 Bari, Italy.
CNR, Istituto di Fotonica e Nanotecnologie, Sede di Bari, 70125 Bari, Italy.
Nat Commun. 2018 Aug 13;9(1):3223. doi: 10.1038/s41467-018-05235-z.
Label-free single-molecule detection has been achieved so far by funnelling a large number of ligands into a sequence of single-binding events with few recognition elements host on nanometric transducers. Such approaches are inherently unable to sense a cue in a bulk milieu. Conceptualizing cells' ability to sense at the physical limit by means of highly-packed recognition elements, a millimetric sized field-effect-transistor is used to detect a single molecule. To this end, the gate is bio-functionalized with a self-assembled-monolayer of 10 capturing anti-Immunoglobulin-G and is endowed with a hydrogen-bonding network enabling cooperative interactions. The selective and label-free single molecule IgG detection is strikingly demonstrated in diluted saliva while 15 IgGs are assayed in whole serum. The suggested sensing mechanism, triggered by the affinity binding event, involves a work-function change that is assumed to propagate in the gating-field through the electrostatic hydrogen-bonding network. The proposed immunoassay platform is general and can revolutionize the current approach to protein detection.
目前，通过将大量配体引导到纳米级换能器上的少数几个识别元件的序列中的单结合事件中，已经实现了无标记的单分子检测。这种方法本质上无法在大量介质中感知信号。通过利用高度密集的识别元件来模拟细胞在物理极限下的感应能力，我们使用毫米级尺寸的场效应晶体管来检测单个分子。为此，栅极通过自组装单分子层 10 个捕获抗免疫球蛋白 G 进行生物功能化，并赋予氢键网络以实现协同相互作用。在稀释的唾液中，我们惊人地证明了选择性和无标记的单分子 IgG 检测，同时还在整个血清中检测了 15 个 IgG。所提出的传感机制由亲和结合事件触发，涉及工作函数的变化，据推测，该变化将通过栅极中的静电氢键网络在栅极电场中传播。所提出的免疫测定平台具有通用性，可以彻底改变当前的蛋白质检测方法。
