Renewable energy harvesting technologies will become potential alternatives in near future by ameliorating global problems such as climate changes and energy related environmental issues for instance global warming and air pollution. Among various energy harvesting systems, triboelectric energy nanogenerators (TENGs) became key candidates via contact electrification concept, that has been rapidly developed and significant efforts have been made to enhance the output power densities. Herein, self-powered smart anti-theft alarm sensor was demonstrated by fabricating TENG. Initially, lead free strontium doped bismuth ferrite (Sr:BiFeO<inf>3</inf>; BSFO) nanomaterials were synthesized via facile solid state reaction process. The BSFO nanomaterials with dielectric constant are mixed with polydimethylsiloxane (PDMS) polymer to fabricate PDMS-BSFO composite layer for TENG fabrication. The biomechanical energy harvesting of fabricated TENGs are operated under contact separation mode and respective electrical output metrics were compared to establish optimal BSFO concentration, operation frequency, force and humidity conditions. The BSFO-TENG delivered 4.71 W/m2 of power density at 60 MΩ load resistance. Long-term operational stability of fabricated TENGs shows robustness and durability with consistent output performance for more than 10,000 cycles. Designed TENG illuminated 120 LEDs, powered the digital clock, and harvested significant electrical energy from regular human activities. To enable the commercial viability of the designed system, the device is integrated into anti-theft smart wallet to demonstrate its ability for self-powered security applications by providing reliable and continuous power without requiring external energy sources. This study offers practical methods for creating high-performance TENGs with practical uses in energy harvesting and intelligent sensing technologies. © 2025 Elsevier B.V., All rights reserved.