Construction of an Ultrasensitive Molecularly Imprinted Virus Sensor Based on an "Explosive" Secondary Amplification Strategy for the Visual Detection of Viruses.

Viral outbreaks have caused great disruptions to the economy and public health in recent years. The accurate detection of viruses is a key factor in controlling and overcoming epidemics. In this study, an ultrasensitive molecularly imprinted virus sensor was developed based on an "explosive" secondary amplification strategy. Magnetic particles coated with carbon quantum dots (Fe3O4@CDs) were used as carriers and fluorescent probes, while aptamers were introduced into the imprinting layer to enhance the specific recognition of the target virus enterovirus 71 (EV71). When EV71 was captured by the imprinted particles, the fluorescence of the CDs was quenched, especially after binding to the aptamer-modified ZIF-8 loaded with a large amount of phenolphthalein, thereby resulting in signal amplification. Then, when adjusting the pH of the solution to 12, the decomposition of ZIF-8 released phenolphthalein, which turned the solution red, leading to the second "explosive" amplification of the signal. Therefore, the detection of EV71 with ultrasensitivity was achieved, which allows for visual detection by the naked eye in the absence of any instruments. The detection limits for fluorescence and visualization detection were 8.33 fM and 2.08 pM, respectively. In addition, a satisfactory imprinting factor of 5.4 was achieved, and the detection time only needed 20 min. It is expected that this fluorescence-colorimetric dual-mode virus molecularly imprinted sensor will show excellent prospects in epidemic prevention and rapid clinical diagnosis.

Photonic and Magnetic Dual-Responsive Molecularly Imprinted Sensor for Highly Specific Recognition of Enterovirus 71.

The specific identification and detection of a virus are the critical factors to identify and control an epidemic situation. In this study, a novel photonic-magnetic responsive virus-molecularly imprinted photochemical sensor was constructed for recognition of enterovirus 71. As designed, the double-bond-modified magnetic metal organic framework and 4-(4'-acryloyloxyazo) benzoic acid were used as a magnetic carrier and light-responsive functional monomer, respectively. The structure of the recognition site of the virus-molecularly imprinted nanospheres can be photo-switched between two different structures to achieve rapid release and specific binding to the target virus. Additionally, the introduction of a magnetic core enables a rapid separation and recycling of imprinted particles. The device achieves a performance with high-specificity recognition (imprinting factor = 5.1) and an ultrahigh sensitivity with a detection limit of 9.5 × 10-3 U/mL (3.9 fM). Moreover, it has good reproducibility and can be stored for as long as 6 months. Thus, the approach used in this work opens a new avenue for the construction of multiresponsive virus sensors.

A novel fluorescence molecularly imprinted sensor for Japanese encephalitis virus detection based on metal organic frameworks and passivation-enhanced selectivity.

Accurate detection of viruses is of great significance in preventing further spreading of infections and developing appropriate clinical treatment. Herein, a fluorescence molecularly imprinted sensor based on a metal-organic framework with high selectivity and high sensitivity at concentrations down to the picomolar (pmol) level was developed to recognize Japanese encephalitis virus (JEV). In this work, zinc acrylate was used as the functional monomer to form molecularly imprinted polymers on the surface of a silicon-modified metal organic frameworks via free radical polymerization. Polyethylene glycol (PEG) was then used as a blocking agent to enhance the ability of polymers to specifically recognize the template virus. Under optimal experimental conditions, the polymers exhibit a wide range of detection, 50 pmol L-1 to 1400 pmol L-1, within 20 min, a low detection limit (13 pmol L-1), and good selectivity (IF = 4.3). These advantages enable this molecularly imprinted (MIP) sensor for important practical application value and significance in the detection and prevention of viruses.

Fast and sensitive detection of Japanese encephalitis virus based on a magnetic molecular imprinted polymer-resonance light scattering sensor.

A magnetic surface molecularly imprinted-resonance light scattering sensor was developed for rapid and highly sensitive detection of Japanese encephalitis virus (JEV). To prepare the surface imprinted polymer, Fe3O4 microspheres were selected as imprinting substrates which coated by silicon. Aminopropyl-triethoxysilane (APTES) as functional monomers for fixing template molecules JEV through a polymerization process of tetraethyl-orthosilicate (TEOS). The target virus JEV could be captured by the imprinted particles fastly and selectively, resulting in an increase of the RLS intensity. The results of RLS analysis proved that the obtained imprinted nanoparticles exhibited excellent specific recognition ability and high selectivity for the template virus (JEV). Furthermore, the response time of the sensor is within 20 min, which is much shorter than the previous works. The sensor with convenient separation and the limit of detection was 1.3 pM. These experimental results show that the proposed strategy is expected to achieve rapid and sensitive detection of JEV in practical applications.