Electronic Detection of MicroRNA at Attomolar Level with High Specificity

Abstract

Small RNA (19-23 nucleotides) molecules play an important role in gene regulation, embryonic differentiation, hematopoiesis, and a variety of cancers. Here, we present an ultrasensitive, extremely specific, label-free, and rapid electronic detection of microRNAs (miRNAs) using a carbon nanotubes field-effect transistor functionalized with the Carnation Italian ringspot virus p19 protein biosensor. miRNA-122a was chosen as the target, which was first hybridized to a probe molecule. The probe-miRNA duplex was then quantified by measuring the change in resistance of biosensor resulting from its binding to p19, which selects 21-23 bp RNA duplexes in a size-dependent but sequence-independent manner. The biosensor displayed a wide dynamic range up to 10(-14) M and was able to detect as low as 1 aM miRNA in the presence of a million-fold excess of total RNA, paving the way for simple, point-of-care, low-cost early detection of miRNA as a biomarker in diagnosis of many diseases, including cancer.

An electrochemical ELISA-like immunosensor for miRNAs detection based on screen-printed gold electrodes modified with reduced graphene oxide and carbon nanotubes

“…A recent approach uses protein 19 (p19), which is known to specifically bind to miRNA.DNA hybrids (Labib et al, 2013;Ramnani et al, 2013). The binding of protein to miRNA.DNA hybrids, generates steric hindrance on the electrode surface or change in conductivity of carbon nanotubes.…”

Label-Free Direct Detection of MiRNAs with Poly-Silicon Nanowire Biosensors

“…Previously, Zhang reported that resistance was measured at 0.1V and mean value was calculated from 25 measurements [17,24]. However, in standard integrated circus study, electronic examination was usually performed in a range of voltage but not at a fixed voltage [20,25]. From the initial screening, we found the current was increased with the voltage increased, showing a polynomial curve (S3 File).…”

Intercalation of quantum dots as the new signal acquisition and amplification platform for sensitive electrochemiluminescent detection of microRNA

“…Up to now, with the great achievements of nanotechnology, nanomaterials are widely used in various miRNA detection schemes due to their fascinating properties in connection to colorimetric [17], photoelectrochemical (PEC) [18], electrochemical (EC) [19][20][21][22] and electrochemiluminescent (ECL) [23][24][25] techniques for signal transduction. Among the popular nanomaterials, semiconductive quantum dots (QDs) have emerged as excellent candidates in biosensor applications attributing to their specific optical and EC properties, which can act as signal tags to trace the recognition events through the target-induced fluorescent or ECL emission variation, or the current change of the metal ions released from the acid-dissolved QDs [24].…”