Peroxidase-Mimicking DNAzyme Modulated Growth of CdS Nanocrystalline Structures in Situ through Redox Reaction: Application to Development of Genosensors and Aptasensors

• Published in: Analytical chemistry (Washington) 2014-10, Vol.86 (20), p.10059-10064
• Main Authors: Garai-Ibabe, Gaizka, Möller, Marco, Saa, Laura, Grinyte, Ruta, Pavlov, Valeri
• Format: Article
• Language: English
• Subjects: Aptamers, Nucleotide - analysis; Assaying; Base Sequence; Biomarkers; Cadmium Compounds - chemistry; Cadmium sulfides; Deoxyribonucleic acid; DNA; DNA Primers; DNA, Catalytic - metabolism; Enzymes; Fluorescence; Low molecular weights; Molecular Mimicry; Molecular Structure; Molecular weight; Nanocrystals; Nanostructures; Oxidation-Reduction; Peroxidases - metabolism; Platforms; Sensors; Sulfides - chemistry
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac502360y

This work demonstrates the use of the peroxidase-mimicking DNAzyme (peroxidase-DNAzyme) as general and inexpensive platform for development of fluorogenic assays that do not require organic fluorophores. The system is based on the affinity interaction between the peroxidase-DNAzyme bearing hairpin sequence and the analyte (DNA or low molecular weight molecule), which changes the folding of the hairpin structure and consequently the activity of peroxidase-DNAzyme. Hence, in the presence of the analyte the peroxidase-DNAzyme structure is disrupted and does not catalyze the aerobic oxidation of l-cysteine to cystine. Thus, l-cysteine is not removed from the system and the fluorescence of the assay increases due to the in situ formation of fluorescent CdS nanocrystals. The capability of the system as a platform for fluorogenic assays was demonstrated through designing model geno- and aptasensor for the detection of a tumor marker DNA and a low molecular weight analyte, adenosine 5′triphosphate (ATP), respectively.