Abstract: The present invention provides tissue sealant compositions and vasculature closure devices useful for the optical detection of tissue seal and/or clot formation. Compositions and devices of the present invention comprise optical dyes which undergo an observable change as the compositions and/or devices are incorporated into a tissue seal and/or clot, for example a change in fluorescence quantum yield and/or a change in visual color including a change in emission and/or absorption wavelength. Tissue sealants and vasculature closure devices of the present invention are useful for visualizing seal and/or clot formation, for example, during or after surgical procedures, after catheter removal, etc. The present invention further provides methods for formation and optical detection of tissue seals or vasculature puncture closures as well as medical kits useful for the formation and optical detection of tissue seals or vasculature puncture closures.