A highly reliable transitional flow-based integrated self-powered catechol sensor (SPCS) proposed for the detection of organic contaminants in water samples. Here the cost-effective hollow tube-shaped piezoelectric nanogenerator (TFPNG-SPCS) by the BiFeO3 nanoparticles works as an SPCS. The obtained ferroelectric remnant polarization and coercive voltages are 0.089 μC/cm2 and 223 V at 1 Hz frequency. The TFPNG device delivers an instantaneous peak-to-peak power density of 2.624 mW/m2 at 500 MΩ. The classification between physical and chemical stimuli is possible through in-tunnel transitional flow and converts them into a readable electrical signal. The proposed TFPNG-SPCS sensor has good selectivity, reasonable sensitivity, eco-friendly, and detection limits down to 10.2 μM, having a linear relationship with catechol concentrations. © 2020 Elsevier B.V.