Protein Electrocatalysis for Direct Sensing of Circulating MicroRNAs

Abstract

MicroRNAs (miRNAs) are potentially useful biomarkers for diagnosis, classification, and prognosis of many diseases, including cancer. Herein, we developed a protein-facilitated electrocatalytic quadroprobe sensor (Sens(PEQ)) for detection of miRNA signature of chronic lymphocytic leukemia (CLL) in human serum. The developed signal-ON sensor provides a compatible combination of two DNA adaptor strands modified with four methylene blue molecules and electrocatalysis using glucose oxidase in order to enhance the overall signal gain. This enhanced sensitivity provided the response necessary to detect the low-abundant serum miRNAs without preamplification. The developed Sens(PEQ) is exquisitely sensitive to subtle π-stack perturbations and capable of distinguishing single base mismatches in the target miRNA. Furthermore, the developed sensor was employed for profiling of three endogenous miRNAs characteristic to CLL, including hsa-miR-16-5p, hsa-miR-21-5p, and hsa-miR-150-5p in normal healthy serum, chronic lymphocytic leukemia Rai stage 1 (CLL-1), and stage 3 (CLL-3) sera, using a non-human cel-miR-39-3p as an internal standard. The sensor results were verified by conventional SYBR green-based quantitative reverse-transcription polymerase chain reaction (RT-qPCR) analysis.

Emerging Biosensing Approaches for microRNA Analysis

“…An LOD of 100 fM was reported using this assay, coined Sens Q , and multiplexing capabilities were demonstrated by the simultaneous quantitation of 3 miRNAs. 113 The mechanism of this promising detection platform is shown in Figure 8B.…”

“…The power of this strategy was sown by detecting three miRNAs in parallel. Reproduced from Labib, M.; Khan, N.; Berezovski, M. V. Analytical Chemistry 2015, 87, 1395–1403 (ref 113). Copyright 2015 American Chemical Society.…”

A novel diagnostic biosensor for distinguishing immunoglobulin mutated and unmutated types of chronic lymphocytic leukemia

“…Thus, the presented impedimetric genosensor has the potential to be clinically useful for diagnosis of type of CLL in serum samples. Although the sensors for diagnosos and detection of CLL have been reported by some researchers (Labib et al, 2015(Labib et al, , 2013Ensafi et al, 2011;Lin et al, 2007), as the date of this manuscript, this is the first sensor that effectively differentiates to Ig-mutated and Ig-unmutated CLL. The developed DNA biosensor offers a more convenient research tool for the identification of two types of CLL.…”

Electrochemical biosensors based on nanomodified screen-printed electrodes: Recent applications in clinical analysis

“…In the recent years, many examples have been proposed for the electrochemical detection of DNA and RNA sequences using disposable electrodes [64][65][66][67][68][69][70][71]. Among these, many are those based on different signal amplification procedures that allow to achieve very low detection limits [72][73][74][75][76][77][78][79][80].…”