A generic point of care based portable device and method thereof as a platform technology for detecting pathogenic infection via nucleic acid based testing achieving sample-to-result integration, comprising the following interconnected stand-alone modules: a thermal unit for executing piece-wise isothermal reactions in a pre-programmable concomitant fashion without necessitating in-between operative intervention; a colorimetric detection unit seamlessly interfaced with smartphone-app based analytics for detecting the target analyte. The said platform technology is thus capable of detecting targeted pathogen-associated RNA by coupling additional complementary DNA probe hybridization combined with isothermal reaction purposed for reverse transcription of RNA followed by amplification of the resulting c-DNA as well as subsequent specific binding of the same in a single user-step in a concomitant fashion and its smartphone-enabled interpretation, in a generic modular format that renders operative suitability outside controlled laboratory environment in a user-friendly manner, with predictive accuracy favorably comparable with gold standard RT-PCR tests.