based on the direct formation of molecularly imprinted polymer on gold electrode , the present invention provides a peptide sensor for the detection of low - molecular - weight peptides . a new cross - linking monomer , 2 is employed to attach the surface of the chip and to copolymerize with other monomers . interestingly , n - benzylacrylamide participating both polymerization and recognition is carried out in an aqueous environment . using quartz crystal microbalance detection , short peptides can be monitored by their interaction with plastic antibodies specific for the target peptides . the selectivity of molecularly imprinted polymer and the sensitivity of such artificial biosensors have collaborated to differentiate traces of oxytocin and vasopressin to the ng / ml scale .