基于发夹型核酸探针的高特异性识别能力以及结晶紫与单、双链DNA结合后荧光强度的差异，以发夹型核酸作为探针，构建了一种非标记型检测p53抑癌基因的荧光DNA生物传感器.此传感器不但能够区分完全互补、单碱基突变和随机目标DNA序列，而且还能识别不同突变位点的单碱基突变序列.在0.05～5.00 μmol/L范围内，完全互补目标DNA的浓度与体系的荧光增强效率呈线性关系，检出限为5×10-8mol/L.该方法已应用于检测正常和单碱基突变的p53基因.

A label-free fluorescence biosensor has been developed for detection of p53 tumor suppressor gene based on the specific recognition of hairpin DNA and fluorescence difference derived from interactions of crystal violet (CV) with the ssDNA and dsDNA. The results indicated that this method can easily discriminate complementary target DNA from single-base mutation oligonucleotide and random oligonucleotide. And it also could distinguish the mutation site of single-base mutation oligonucleotide. In the range of 0.05-5 μmol/L，the concentration of complementary sequence was linear with the change of the fluorescence signal of CV, and the detection limit was 50 nmol/L. This method can be used in detecting normal and single-base mutation p53 gene.