Organic Field Effect Transistor With Thiolated ?-cyclodextrin Supramolecule Sensitized Gate And Its Chiral Sensing

Chirality is a feature of the universe,embodied in the generation and evolution of life.Different enantiomers have the same physical and chemical properties,but often exhibit different physiological activities and pharmacological effects in biological systems,which makes chiral resolution very important in the biological and modern pharmaceutical industries.Organic field effect transistors(OFETs)are widely used in chemical and biosensors due to their low power consumption,high sensitivity,fast response,online analysis,and"mark-free"detection capabilities.However,Discrimination of chirality by field effect transistors(FETs)is a great challenge because enantiomers possess exactly identical charge and hence chiral recognition solely relates to spatial effects,while the working principle for most FET sensors is based on intrinsic charge of analytes.In this work,a chiral organic field effect transistor(COFET)with a self-assembled thiolated?-cyclodextrin(SH-?-CD)monolayer modified gold top-gate electrode is developed to afford rapid,highly sensitive and real-time chiral discrimination for various enantiomers.Well-defined sensing results are achieved for diverse acidic enantiomers with a lowest detection concentration(LDC)of 10^-12 M.The chiral sensing mostly depends on the changed work function of top electrode and hence varied surface potential at the gate/solution interface caused by the target-induced CD enantiomer complex formation with different geometry for each isomer,which is independent of the intrinsic charge of the analytes.This proof-of-concept allows chiral resolution even for uncharged enantiomers,which still remains as a major hurdle for FET-based sensors.Furthermore,the COFET shows composition dependence for its response towards enantiomers mixture of phenylalanine(Phe)as well as a“real world”pharmaceutical drug(ibuprofen),which proves the potentiality of the COFET for quantitative chiral analysis of commercial pharmaceutical drugs.Finally,the seven-mercapto-?-cyclodextrin was used as the sensing layer of the OFET sensor.The sensor based on seven-mercapto-?-cyclodextrin showed faster and more sensitive response than that of is higher stability and sensitivity.