Smartphone-assisted Hepatitis C detection assay based on magnetic levitation

Abstract

This work describes development of smartphone-assisted magnetic levitation assay for Point-of-Care (PoC) applications. Magnetic levitation is a technique that detects and separates particles based on their density differences in a magnetic field. Observation of the levitated micro-particles is mainly performed by light microscope or additional optical components, which mostly limits applicability of the magnetic levitation technique for PoC diagnostics. In this paper, we demonstrated the capability of the smartphone assisted-magnetic levitation platform for Hepatitis C (HCV) detection assay. This method utilizes microsensor beads (MS beads) that are functionalized with anti-HCV NS3 antibody. First, the magnetic levitation platform was optimized via density marker polyethylene beads (DMB); then HCV NS3 protein was successfully detected based on levitation height differences of MS beads caused by density changes. The capability of the magnetic levitation platform for HCV detection was determined as almost 10-fold sensitive compared to conventional techniques such as enzyme-linked immunosorbent assay (ELISA). The imaging capability and resolution of the setup was improved over previously used configurations, and the developed platform enabled visualization of micro-scale objects only by smartphone assistance. This method requires no power, it is an easy-to-use and cost effective, therefore it could be easily adaptable to varied sensing assays as PoC tool.