Paper microchip with a graphene-modified silver nano-composite electrode for electrical sensing of microbial pathogens

• Published in: Nanoscale Vol. 9; no. 5; pp. 1852 - 1861
• Main Authors: Safavieh, Mohammadali, Kaul, Vivasvat, Khetani, Sultan, Singh, Anupriya, Dhingra, Karan, Kanakasabapathy, Manoj Kumar, Draz, Mohamed Shehata, Memic, Adnan, Kuritzkes, Daniel R, Shafiee, Hadi
• Format: Journal Article Web Resource
• Language: English
• Published: England Royal Society of Chemistry 02.02.2017
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c6nr06417e

Rapid and sensitive point-of-care diagnostics are of paramount importance for early detection of infectious diseases and timely initiation of treatment. Here, we present cellulose paper and flexible plastic chips with printed graphene-modified silver electrodes as universal point-of-care diagnostic tools for the rapid and sensitive detection of microbial pathogens or nucleic acids through utilizing electrical sensing modality and loop-mediated isothermal amplification (LAMP). We evaluated the ability of the developed paper-based assay to detect (i) viruses on cellulose-based paper microchips without implementing amplification in samples with viral loads between 10 and 10 copies per ml, and (ii) amplified HIV-1 nucleic acids in samples with viral loads between 10 fg μl and 10 fg μl . The target HIV-1 nucleic acid was amplified using the RT-LAMP technique and detected through the electrical sensing of LAMP amplicons for a broad range of RNA concentrations between 10 fg μl and 10 fg μl after 40 min of amplification time. Our assay may be used for antiretroviral therapy monitoring where it meets the sensitivity requirement of the World Health Organization guidelines. Such a paper microchip assay without the amplification step may also be considered as a simple and inexpensive approach for acute HIV detection where maximum viral replication occurs.