Fingerprints mapping and biochemical sensing on smartphone by electrochemiluminescence

Electrochemiluminescence (ECL) is a kind of optical radiation process triggered by electrochemistry, which has been one of the most important strategies in analytical chemistry and biosensing. Recently, smartphone, as one of the widely-used mobile device, has provided a attractive solution as simple yet powerful sensing platform to satisfy the needs of on-site inspection. Here, ECL on smartphone was put forward for fingerprints mapping and biochemical sensing. The smartphone-based system integrated both electrochemical excitation and optical analysis by built-in functional modules “all in one phone”. Typical enhanced luminescence analysis of nicotine, quenched luminescence analysis of trinitrotoluene (TNT) demonstrated the availability of the phone-based ECL system for biochemical sensing. Furthermore, multimode imaging analysis including color induction, gray processing, and binary extraction on smartphone were used for fingerprints mapping. The grain information of fingerprints was clearly displayed on the luminescence images, even the sweat pores on fingerprints were visible to naked eyes. Finally, in situ sensing of exogenous substances on fingerprints, such as nicotine and TNT were also accomplished by the phone. Results indicated the remarkable performances of the system in ECL, especially in the fields of biochemical sensing and imaging analysis. Because fingerprints were widely used to unlock phones, the combination of fingerprints imaging and sensing on smartphone would be contributed to the development of personal medicine, public health monitoring, and mobile care testing.