Nucleic acid testing(NAT)promises stable,safe,selective and specific detection of infectious and inherited diseases.However,conventional technologies,such as gel electrophoresis,ultraviolet spectrometry and fluorescent PCR,are labor-intensive and time-consuming,and require specialized instruments and professional staff.In this study,we have developed a new diaphragm mass biosensor based on polyvinylidene fluoride(PVDF)piezoelectric film for detection of nucleic acids.Using a sequence of human immunodeficiency virus type ?(HIV-1)as a model analyte,we designed a capture probe immobilized on the gold film of the biosensor via Au-S reaction.To improve the specificity of the biosensors,we employed 6-mercapto-1-hexanol(MCH)as a blocking reagent after probe immobilization.Via the nucleic acid hybridization between capturing probe and target analyte,the real mass load added on the diaphragm was proportional to the amount of target nucleic acids.Fluorescent measurement was used in the study to check the whole experiment and served as a control.The biosensor developed here can provide a cost-effective platform for NAT,thus holding potential for disease screening.