Development of an Aptamer-Based Electrochemical Microfluidic Device for Viral Vaccine Quantitation

Abstract

Global deployment of vaccines poses significant challenges in the distribution and use of the accompanying immunoassays, one of the standard methods for quality control of vaccines, particularly when establishing assays in countries worldwide to support testing/release upon importation. This work describes our effort toward developing an integrated, portable device to carry out affinity assays for viral particles quantification in viral vaccines by incorporating (i) aptamers, (ii) microfluidic devices, and (iii) electrochemical detection. We generated and characterized more than eight aptamers against multiple membrane proteins of cytomegalovirus (CMV), which we used as a model system and designed and fabricated electrochemical microfluidic devices to measure CMV concentrations in a candidate vaccine under development. The aptamer-based assays provided a half maximal effective concentration, EC 50 , of 12 U/mL, comparable to that of an ELISA using a pair of antibodies (EC 50 60 U/mL). The device measured relative CMV concentrations accurately (within ±10% bias) and precisely (11%, percent relative standard deviation). This work represents the critical first steps toward developing simple, affordable, and robust affinity assays for global deployment without the need for sensitive equipment and extensive analyst training.

Microfluidic devices for photo-and spectroelectrochemical applications

“…The choice of design and fabrication method for microfluidics with integrated electrodes, is strongly dependent on the application, user settings, constraints from materials and type of samples (wetting properties and viscosity), with designs often not directly transferable between applications [10,11] (see Figure 2ab). Commonly, a straightforward single channel design, aiming at accurate flow control, is used.…”