Enzyme-free colorimetric detection of MicroRNA-21 using metal chelator as label for signal generation and amplification

• Published in: Analytica chimica acta Vol. 1052; pp. 145 - 152
• Main Authors: Piao, Jiafang, Zhao, Qian, Zhou, Dianming, Peng, Weipan, Gao, Weichen, Chen, Minghui, Shu, Guiming, Gong, Xiaoqun, Chang, Jin
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 04-04-2019; Elsevier BV
• Subjects: Amplification; AuNPs; Cancer; Chelates; Chelating Agents - chemistry; Chelation; Colorimetry; Colorimetry - methods; Diagnosis; Edetic acid; Edetic Acid - chemistry; EDTA•2Na; Ethylenediamine; Ethylenediaminetetraacetic acids; Gold; Humans; Metals; Microparticles; microRNA; MicroRNAs; MicroRNAs - analysis; miRNA; Nanoparticles; Oligonucleotide Probes - chemistry; Oligonucleotides; Plasmonic signal; Ribonucleic acid; RNA; Sandwich structures; Signal generation; Silicon dioxide; Temperature; Tumor markers; EDTA•2Na; microRNA; Plasmonic signal; AuNPs
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2018.11.044

MicroRNAs (miRNAs) were reported to be potential tumor markers for early diagnosis of cancer. Due to its short sequence, low expression level and high susceptibility to degradation, the stable and sensitive detection method of miRNAs is arduous to establish. In this work, we designed a metal chelator (ethylenediamine tetraacetic acid disodium salt, EDTA•2Na) labeled oligonucleotides as the plasmonic signal supraregulator probe to control the generation of gold nanoparticles (AuNPs). Based on another complementary oligonucleotides of target miRNA labeling SiO2 microparticles (SiO2MPs) as the detecting platform, EDTA•2Na labeled oligonucleotide probes were immobilized on the SiO2 platform through the sandwich structure in the presence of target miRNA. The sandwich chelating device could further chelate Au3+ to regulate the generation of AuNPs, resulting in colorimetric signal to qualitatively and quantitatively detect the concentration of microRNA-21 (miR-21). The results indicate that the proposed metal chelator -labeled signal amplification method has outstanding sensitivity (LOD = 8.9 fM) and excellent stability, which will be benefit for the early accurate diagnosis of miRNAs.
An enzyme-free biosensor based on metal chelator (EDTA•2Na), by hybridizing with target (miR-21) to chelating Au3+ ions and regulating the growth of gold nanoparticles to create a gradient tonality for sensitive detection. [Display omitted]
•We designed a simple, sensitive and stable colorimetric biosensor for miRNA detection based on metal chelator.•The biosensor shows stable detection capability within 30 days and performs well in detecting clinical human blood samples.•The limit of detection of miR-21 is down to 8.9 fM.