Synthesis of a three-dimensional interconnected carbon nanorod aerogel from wax gourd for amperometric sensing

The authors describe a method for synthesis of a three-dimensional (3D) interconnected carbon nanorod aerogel (3D-ICNA) starting from wax gourd ( Benincasa hispida ) which is a low-cost biomass. The 3D-ICNA possesses unique 3D interconnected and porous nanostructure, with abundant edge-plane-like defective sites, a large specific surface area (823 m 2  g −1 ) and a large pore volume (0.12 cm 3  g −1 ). This makes the material attractive in terms of electrochemical sensing. To validate the feasibility, the voltammetric response towards ferricyanide, hydrogen peroxide (H 2 O 2 ), acetaminophen, ascorbic acid (AA), dopamine, uric acid and epinephrine was investigated by using a glassy carbon electrode (GCE) modified with 3D-ICNA. The modified GCE shows higher electron-transfer capacity than a conventional GCE. In addition, as an electrochemical sensor for AA or H 2 O 2 , the electrode exhibits better analytical performance with lower detection limit [3.5 μM for AA or 0.68 μM for H 2 O 2 based on 3σ/m criterion (where σ is the standard deviation of the blank and m is the slope of the calibration plot)], wider linear range and higher sensitivity (0.14, 0.11 and 0.080 μA μM −1  cm −2 for AA or 0.24 and 0.20 μA μM −1  cm −2 for H 2 O 2 ) compared to a plain GCE or a carbon nanotube-modified GCE. The modified GCE exhibits a large potential for the amperometric determination of AA or H 2 O 2 in real samples. By employing the biomass of wax gourd ( Benincasa hispida ) as the precursor, a three-dimensional interconnected carbon nanorod aerogel was prepared. It is shown to be a viable material for the construction of an advanced electrochemical sensor for H 2 O 2 and ascorbic acid.