Spectrometric analysis of chemiluminescence resonance energy transfer on a smartphone-enabled analytical device

The design of a smartphone-enabled analytical device (SEAD) is reported that detects and analyzes chemiluminescence resonance energy transfer (CRET) between donor and acceptor molecules during a chemical reaction process. The proposed analytical tool is compact, user-friendly, cost-efficient, and provides an alternative platform suitable for in-field investigations. The chemiluminescence (CL) reaction protocol adopted generates violet-blue light signal with peak wavelength emission at ~ 425 nm that occurs due to chemical excitation of the donor species. In the presence of an acceptor molecule, a non-radiative energy transfer occurs from the excited donor to the acceptor molecule. As a result of this energy transfer, the excited acceptor molecule undergoes return to lower exitation state  emitting radiation at a longer wavelength (~ 514 nm). The emergence of a secondary emission peak due to CRET can be detected using the designed SEAD. The usability of the sensing platform has been demonstrated through the detection of silver ions (Ag⁺) in aqueous solutions with a limit of detection (LOD) of 17.04 μM. The sensing scheme proposed is highly selective. The obtained results highlight that the designed sensing scheme could emerge as an alternative platform for monitoring of chemical and environmental parameters through CRET-based analysis.