Solution-gated Graphene Field Effect Transistor Sensor Based on Crown Ether Functionalization for the Detection of Mercury Ion br

Hg2+is a heavy metal with bioaccumulation and toxicity???causing serious damage to the environment andhuman health.Therefore???it is very necessary to develop a convenient Hg2+sensor.Because of the excellent perfor???mance of graphene field-effect transistors???this work prepared a solution-gated graphene field effect transistor???SGGT???sensor with crown ether functionalized gate.The selectivity of the transistor sensor was achieved through thesize effect of crown ether and the chelation of N and S atoms on the crown ether???which makes the sensor recognizeHg2+specifically.The research showed that the SGGT sensor is more sensitive than traditional electrochemistry due toits inherent signal amplification function???which is2-3orders of magnitude lower???and the detection limit is as low as1x10-12mol/L in this study.In the detection range of1x10-12-1x10-7mol/L???the result exhibited an excellentlinear relationship between the change value of the Dirac point and the logarithm of the target concentration.More???over???it showed extremely high selectivity to Hg2+.The test of the real samples in the lake water was satisfactory???inwhich the detection standard deviation of Hg2+is1.10%-3.77%.The study indicated that the transistor sensor candetect Hg2+in complex samples with high selectivity and sensitivity.