Aminophenol Molecular Capture Layer for Specific Molecular Sensing with Field-Effect Devices

There is an urgent need today for interface management with recognition layers composed of short receptor molecules, with excellent specificity and affinity toward a target molecule, for a wide range of sensing applications. The current work demonstrates a specific detection of a G-type nerve agent, which is based on a nucleophilic substitution reaction between the surface-bound 4-amino-2-((dimethylamino)methyl)phenol (amino-2-DMAMP) receptors and the diethyl chlorophosphate (DCP) simulant. The specificity and affinity of 2-DMAMP toward DCP are demonstrated with ³¹P-nuclear magnetic resonance (NMR) and electrospray ionization mass spectrometry (ESI-MS/MS). The specificity of the proposed recognition layer is utilized and demonstrated through the design and realization of an electronic chemosensor using the meta-nanochannel field-effect transistor (MNC FET). The SiO₂ sensing area of the MNC FET is functionalized with amino-2-DMAMP receptors using amine-based chemistry, and the response toward DCP is quantified. An excellent specificity is demonstrated, coupled with a limit of detection of 1 pg/mL, a dynamic range of 8 orders of magnitude, and excellent linearity and sensitivity. The high specificity and affinity of the recognition layer coupled with the high electronic grade of the MNC FET pave the way to specific, label-free, quantitative, low-cost, easy-to-operate, and field-deployable sensors.