High surface area cobalt aluminium layered double hydroxide printed electrodes for flexible supercapacitor and on-chip electrochemical bacterial lysing

Abstract

This article describes the successful use of high surface area cobalt aluminium layered double hydroxide as an effective electrode material for fabricating highly flexible printed supercapacitor and electrochemical bacterial lysing chips. The flexible supercapacitor showed a high areal capacitance of 4.16 mF cm−2 at 0.4 mA cm−2 current density with 1.30 μWh cm−2 areal energy density and 301.04 μWcm−2 areal power density. Most importantly, the developed supercapacitor exhibited 91.32% initial areal capacitance even after 5000 continuous charge-discharge cycles and excellent mechanical stability over different bending states. An electrochemical chip for bacterial lysing was fabricated using a PDMS reservoir and catalyst-coated screen-printed carbon electrode. On-chip lysing of Gram-negative and Gram-positive bacteria was completely achieved at an applied potential of 3.5 V in 2 minutes, which is 1 V lower than that required for the unmodified electrode. The electrochemical chip outperforms commercial chemical lysing kits in terms of lysing time, DNA yield, longer DNA strands, and cost.