High Sensitivity Detection of CdSe/ZnS Quantum Dot-Labeled DNA Based on N-type Porous Silicon Microcavities

• Published in: Sensors (Basel, Switzerland) Vol. 17; no. 1; p. 80
• Main Authors: Lv, Changwu, Jia, Zhenhong, Lv, Jie, Zhang, Hongyan, Li, Yanyu
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.01.2017; MDPI
• Subjects: Cadmium Compounds; Deoxyribonucleic acid; DNA; Hybridization; Labeling; Microcavities; N-type porous silicon; Pore size; Porosity; QD-DNA; quantum dot labeling; Quantum Dots; Qunatum dots; Reflectance; reflectance spectrum; Reflectivity; Refractive index; Refractivity; Refractometry; Selenium Compounds; Sensitivity; Sensors; Silicon; Silicon wafers; Sulfides; Zinc Compounds; Zinc sulfides; China; QD-DNA; reflectance spectrum; N-type porous silicon; quantum dot labeling
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s17010080

N-type macroporous silicon microcavity structures were prepared using electrochemical etching in an HF solution in the absence of light and oxidants. The CdSe/ZnS water-soluble quantum dot-labeled DNA target molecules were detected by monitoring the microcavity reflectance spectrum, which was characterized by the reflectance spectrum defect state position shift resulting from changes to the structures' refractive index. Quantum dots with a high refractive index and DNA coupling can improve the detection sensitivity by amplifying the optical response signals of the target DNA. The experimental results show that DNA combined with a quantum dot can improve the sensitivity of DNA detection by more than five times.