Abstract: The present invention provides a sensing electrode, an electrochemical sensing system using the sensing electrode, methods of preparing and using the sensing electrode and the electrochemical sensing system. The sensing electrode includes a base electrode having a conductive surface, and a coating layer formed on the conductive surface. The coating layer has cavities or holes, each of which can be filled with, bound to, or occupied by, an analyte molecule. A decrease of conductivity of the sensing electrode is correlated to the number of cavities or holes that are filled with, bound to, or occupied by, the molecules of the analyte. The invention exhibits numerous technical merits such as suitability for field application, high sensitivity to analyte such as PFOA or PFAS at 1 ppt level, rapid response within minutes, and superior selectivity against interferences such as PFDA, PFOS, PFOSA, and PFHxA, among others.

Abstract: 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.

Abstract: 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.

Abstract: 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.