A double fluorescent particle comprises: a core with a first fluorescence; and a molecularly imprinted polymer (MIP) shell with a second fluorescence; wherein the MIP is an organic polymer comprising elements selected from the group consisting of: C, H, O, N, P, and S; wherein the MIP is adapted to selectively bind to a cell surface structure; wherein the first fluorescence is generated by an entity selected from the group consisting of: a carbon nanodot, an alkaline earth metal fluoride, a dye-doped polymer, a dye-doped stabilized micelle, a P-dot—i.e. a π-conjugated polymer, a quantum dot doped polymer, a rare earth metal ion doped polymer, a dye-doped silica, a rare-earth ion doped silica, and a rare earth ion doped alkaline earth metal fluoride nanoparticle; wherein the second fluorescence is generated by an entity selected from the group consisting of: a dye, a molecular probe, an indicator, a probe monomer, an indicator monomer, and a cross-linker, and wherein the first and second fluorescence differ at least by an emission wavelength and/or by an excitation wavelength.

The present invention relates to a method for constructing a chromatography test strip for triazophos based on molecular imprinting and electrospinning. The present invention combines electrospinning, molecular imprinting and the immunochromatography test strip technology. Molecularly imprinted T-line (detection limit) is prepared on an NC membrane by electrospinning, and goat anti-mouse IgG is used as C-line (quality control line). With fluorescence changes occurring when triazophos hapten-murine IgG/fluorescein isothiocyanate conjugate (THBu-IgG-FITC) fluorescent probe directly competes with the target triazophos to bind to the molecularly imprinted binding site, a chromatography-fluorescence detection method for triazophos based on molecular imprinting and electrospinning is established. The functional material adsorbing triazophos provided by the present invention adopts a virtual template to avoid template leakage, and can be used in immunochromatography to replace a biological antibody. The functional material has higher selectivity, higher stability, longer service life, and stronger resistance to adverse environment.

The present invention provides a sensing device for detecting an analyte containing a non-metallic element such as F. A working sensor has a 3D array of voids each having a void internal wall. The void internal walls have cavities each having a cavity internal wall made from a material containing the non-metallic element. A binding of the analytes to the cavities induces a detectable variation of the optical property of the 3D array of voids. The invention exhibits numerous technical merits such as high sensitivity, high specificity, fast detection, ease of operation, low power consumption, zero chemical release, and low operation cost, among others.

The present invention provides a novel and efficient process of preparing a highly organized 3D array of particles by stacking multiple 2D arrays of the particles. The 3D array of particles so prepared is used in fabrication of sensors, such as molecular imprinted photonic (MIP) crystal sensor. The sensor has a 3D array of voids each having a void internal wall. The void internal walls have cavities each having a cavity internal wall made from a material containing the non-metallic element. A binding of the analytes to the cavities induces a detectable variation of the optical property of the 3D array of voids. The invention exhibits numerous technical merits such as high sensitivity, high specificity, fast detection, ease of operation, low power consumption, zero chemical release, and low operation cost, among others.

The current COVID-19 pandemic caused by SARS-CoV-2 coronavirus is expanding around the globe. Hence, accurate and cheap portable sensors are crucially important for the clinical diagnosis of COVID-19. Molecularly imprinted polymers (MIPs) as robust synthetic molecular recognition materials with antibody-like ability to bind and discriminate between molecules are provided here as selective elements in such sensors. Provided are detection assemblies comprising electrochemical sensors having ncovNP-MIP film endowed selectivity against SARS-CoV-2 nucleoprotein (ncovNP) and/or ncovS1-MIP film endowed selectivity against SARS-CoV-2 spike 1 (S1). The ncovNP- or ncovS1-MIP are synthesized electrochemically on portable gold thin-film electrodes system via chronocoulometry or cyclic voltammetry. The sensors show excellent detection capabilities, and high discrimination of interfering proteins.

A method for preparing a ratiometric fluorescent sensor for phycoerythrin based on a magnetic molecularly imprinted core-shell polymer is provided. With Fe.sub.3O.sub.4 magnetic nanoparticles as the core, blue fluorescence-emitting carbon quantum dots (B-CDs) are coupled on the surfaces of Fe.sub.3O.sub.4 magnetic nanoparticles, and SiO.sub.2 shells carrying template molecules (phycoerythrin) are grown on the surfaces of Fe.sub.3O.sub.4/B-CDs. Then, the molecularly imprinted polymer SiO.sub.2-MIPs are obtained by eluting the template molecules, that is, Fe.sub.3O.sub.4/B-CDs/SiO.sub.2-MIPs are obtained. Fluorescence emission spectra of the dispersion of Fe.sub.3O.sub.4/B-CDs/SiO.sub.2-MIPs in the presence of different concentrations of phycoerythrin are measured. By fitting the linear relationship between the ratios I.sub.phycoerythrin/I.sub.B-CDs of fluorescence emission peak intensities of phycoerythrin and B-CDs and the molar concentrations of phycoerythrin, the ratiometric fluorescent sensor for phycoerythrin is constructed.

The application provides a method of detecting an analyte in a sample. The method comprises disposing a binding agent in in an electrochemical compartment. The binding agent is configured to bind to an interfering species. The method further comprises disposing a solution comprising a sample in the electrochemical compartment. The sample comprises an analyte and the interfering species. The method then comprises applying a voltage across first and second spaced apart electrodes disposed in the solution, and thereby causing a current to flow through the solution between the electrodes. Finally, the method comprises measuring the current and/or voltage and thereby detecting the analyte.

A method for preparing a ratiometric fluorescent sensor for phycoerythrin based on a magnetic molecularly imprinted core-shell polymer is provided. With Fe.sub.3O.sub.4 magnetic nanoparticles as the core, blue fluorescence-emitting carbon quantum dots (B-CDs) are coupled on the surfaces of Fe.sub.3O.sub.4 magnetic nanoparticles, and SiO.sub.2 shells carrying template molecules (phycoerythrin) are grown on the surfaces of Fe.sub.3O.sub.4/B-CDs. Then, the molecularly imprinted polymer SiO.sub.2-MIPs are obtained by eluting the template molecules, that is, Fe.sub.3O.sub.4/B-CDs/SiO.sub.2-MIPs are obtained. Fluorescence emission spectra of the dispersion of Fe.sub.3O.sub.4/B-CDs/SiO.sub.2-MIPs in the presence of different concentrations of phycoerythrin are measured. By fitting the linear relationship between the ratios I.sub.phycoerythrin/I.sub.B-CDs of fluorescence emission peak intensities of phycoerythrin and B-CDs and the molar concentrations of phycoerythrin, the ratiometric fluorescent sensor for phycoerythrin is constructed.

The present disclosure provides new approaches in developing templated polymer-based chemical receptors. At least some embodiments of the invention use a stimuli-responsive polymer [e.g., poly-Nisopropylacrylamide (pNIPAM)] as a polymer backbone with the incorporation of functional monomers (for analyte recognition). In at least some embodiments of the invention, vinylferrocene may be used as a redox-active label for electrochemical transduction.

The present invention relates to a method of preparing a molecular sensor that is specific for a target molecule having a saccharide or peptide region. The method comprises using the target molecule as a template and incubating the template with a receptor to form a template-receptor complex. A molecular scaffold is formed on a surface around the template-receptor complex such that the receptor and at least a portion of the template are embedded in the scaffold, and the template is removed to produce a cavity defined by the scaffold, such that the cavity is complementary to at least a portion of the saccharide or peptide region of the target molecule.