▎ 摘　　要

The increasing demand for simple, low-cost, rapid, sensitive and label-free methods for the detection of DNA sequences and the presence of single nucleotide polymorphisms (SNPs) has become an important issue in biomedical research. In this work, we studied the performances of several chemically modified graphene nanomaterials as sensing platforms by using the electrochemical impedance spectroscopy technique for the detection. We employed a hairpin DNA as a highly selective probe for the detection of SNP correlated to Alzheimer's disease. We believe that our findings may present a foundation for further research and development in graphene-based impedimetric biosensing.