Components, for example, nanoparticles for detecting and/or treating one or more active carious lesions or microcavities in teeth of a subject are provided. The component or nanoparticle may comprise a biocompatible and biodegradable polymer (e.g., a starch) bearing at least one cationic region and/or having a net positive charge and thereby capable of associating with one or more active and/or early carious lesions on a tooth in an oral cavity of a subject. The components or nanoparticles are optionally water soluble or dispersible. The components or nanoparticle also comprises an imaging agent (e.g., a fluorophore or dye) bonded to the biocompatible and biodegradable polymer. The component or nanoparticle is thus capable of indicating the presence of one or more active carious lesions when the component or nanoparticle is associated therewith. Oral care compositions comprising such compounds/nanoparticles and methods of making and using the same are also provided.