Porous nickel oxide (NiO) microflowers have been successfully synthesized by calcining a coordination microflower without any hard template, seed or using soft template. More importantly, porous NiO microflowers have been applied as effective electrochemical sensor of the tripeptide glutathione (GSH) and electrochemical supercapacitors. The effectively electrochemical GSH sensor of porous NiO microflowers in 0.1 M HAc-NaAc (pH 5.0) solution was the first time evaluated. Moreover, the specific capacitance of porous NiO microflower was up to 1678.4F g(-1) at current density of 0.625 A g(-1), and maintained about 99.7% at 6.25 A g(-1) after 1000 cycles. (C) 2012 Elsevier Ltd. All rights reserved.