In recent years, organic electronics have been explored as a potential paradigm for renewable, transient, and biodegradable systems. In this study, we used fish scales as raw materials for fabricating a biopolymer substrate (BPS) and evaluated its application in an organic metal-insulator-metal capacitor. Evaluation of the morphological and optical properties of BPS revealed an average surface roughness value of 1.19 nm, 90% transmittance in the UV-visible range, and an absorption coefficient of 5.29 cm(-1) at 3.5 eV. Fourier transform infrared spectroscopy showed the presence of amide A, amide I, amide II, and amide III bonds in the substrate, and 42 degrees +/- 5 degrees was the rollover contact angle. The substrate was dissolved in water within 40 min at room temperature and degraded by more than 90% within 30 days in natural soil. Further, mechanical property analysis showed that the substrate exhibited a flexural strength of 8.33 MPa and a tensile strength of 4 MPa. The capacitance density and leakage current of the Al/bovine serum albumin/Pt/BPS structure are found to be 1.05 fF/mu m(2) (1 MHz, 1 V) and 1.15 mu A/cm(2) (at 1 V), respectively. The proposed substrate can be used as a cost-efficient, ecofriendly, biocompatible, and transparent charge storage device for transient electronics in the near future.