Portable dual-function ratio-type triple-emission molecularly imprinted fluorescence sensor for the simultaneous visual detection of hepatitis A and B viruses.

Background: Viral epidemics have long endangered human health and had dramatic impacts on environment and society. The currently known viruses and the rapid emergence of previously unknown viruses lead to an urgent need for effective virus detection strategies. It is important to develop methods that can detect multiple related viruses simultaneously in order to improve detection efficiency and to avoid treatment delays due to misdiagnoses. However, an important practical problem for viruses simultaneously detection is mutual interference between the targets, which is caused by a certain degree of signal superposition.

Results: A portable ratio-based triple-emission molecular imprinting fluorescence sensor was constructed to detect hepatitis A virus (HAV) and hepatitis B virus (HBV) simultaneously, which eliminated background interference and mutual interference between the two targets, and improved detection accuracy. In this sensor, a layer containing blue fluorescent carbon quantum dots (B-CDs) coated with silicon was used as a constant luminescent core to permit ratiometric detection of signals, this layer also affords visual analysis due to its constant blue color. As signal sources to employ yellow-green and red quantum dots, HAV- and HBV-specific molecularly imprinted polymers (MIPs) were prepared by imprinting virus onto the core containing the B-CDs. Under the optimized detection conditions, the simply physically mixing HAV-MIPs and HBV-MIPs in a specific ratio, which leads to non-interfering fluorescence signals and the simultaneous detection of the two target viruses via the rich color visualization under ultraviolet light.

Significance: This strategy provides a simple and low-cost (0.26 ¥/sensor) method for the simultaneous detection of two hepatitis viruses, and provides an avenue for the development of portable methods for the simultaneous detection of similar highly infectious viruses. This self-service sensor also has the potential to be used by patients themselves, reducing pressures on medical staff and decreasing risks of cross-infection.