Graphene-oxide-loaded superparamagnetic iron oxide nanoparticles for ultrasensitive electrocatalytic detection of microRNA

Md Nazmul Islam, Lena Gorgannezhad, Mostafa Kamal Masud, Shunsuke Tanaka, Md Shahriar A. Hossain, Yusuke Yamauchi, Nam Trung Nguyen, Muhammad J.A. Shiddiky

Research output: Contribution to journalArticlepeer-review

40 Citations (Scopus)


We report the electrocatalytic activity of a new class of superparamagnetic nanoparticles, graphene-oxide-loaded iron oxide (GO/IO hybrid material), towards the reduction of ruthenium hexaammine(III) chloride (Ru(NH3)6]3+, RuHex). Leveraging the electrocatalytic activity of the GO/IO hybrid material and the signal enhancement capacity of [Ru(NH3)6]3+/[Fe(CN)6]3− in an electrocatalytic cycle, an ultrasensitive and specific electrochemical sensor was developed for the detection of cancer-related microRNA (miRNA). Using the direct affinity interaction between RNA and graphene oxide, magnetically isolated and purified target miRNA were directly adsorbed onto a screen-printed electrode modified with the GO/IO hybrid material. The detection was enabled by chronocoulometric (CC) readout of charge-compensating [Ru(NH3)6]3+ followed by an enhancement in CC charge display through the Ru(NH3)6]3+/[Fe(CN)6]3− system. We demonstrate an excellent limit of detection of 1.0 fM by accurately detecting miR-21 in synthetic samples and showcase its clinical utility in ovarian cancer cell lines with high sensitivity (ten cells) and good reproducibility (% RSD=<5 %, for n=3).
Original languageEnglish
Pages (from-to)2488-2495
Number of pages8
Issue number17
Publication statusPublished - 03 Sept 2018


Dive into the research topics of 'Graphene-oxide-loaded superparamagnetic iron oxide nanoparticles for ultrasensitive electrocatalytic detection of microRNA'. Together they form a unique fingerprint.

Cite this