Abstract: A method of determining concentration of a target organic compound in a sample, the method comprising dissolving a target sample in an organic solvent to obtain a sample solution, applying a probing device to the sample solution to form a target analyte, wherein the probing device is an SMIP probe comprising a solvatochromic molecularly imprinted polymer, and the SMIP probe comprises a solvatochromic functional group or a solvatochromic functional monomer the colour and/or fluorescence properties of which will change upon coupling or encountering the target organic compound or when the target organic compound is captured by the SMIP probe, and detecting or determining presence and concentration of the target organic compound with reference to a responsive optical signal such as colorimetric, luminescent and/or fluorescent response of the target analyte.