Calixarene Molecules Immobilized on Gold Substrates of QCM Sensors Based on Self-assembled Monolayer Technology

Four calixarene supramolecular compounds, RCT, PCT, MRCT, and TBCA as active materials, were immobilized on gold substrates of quartz crystal microbalance (QCM) sensors by using L-cysteine self-assembled monolayer (SAM) as a linker. The RCT immobilized QCM sensor possessed the best response characteristics for methanol molecule when the assembling concentration of RCT reached 1.0 mg/mL. The frequency shift response value of the RCT immobilized QCM sensor was in direct proportion to the concentration of methanol vapor with a range of 0 similar to 6000 ppm. Comparing with a gas chromatography, the proposed QCM sensor could be well used for the determination of methanol vapor with a recovery rate of 98.01 similar to 103.9 %, and the two methods showed a well consistent examination result. Also, the sensor possessed good reproducibility and stability, showing that the RCT immobilized QCM sensor can be applied for the detection of the methanol vapor of atmospheric polutants in our living environment.