Facile synthesis of flower like copper oxide and their application to hydrogen peroxide and nitrite sensing

<p>Abstract</p> <p>Background</p> <p>The detection of hydrogen peroxide (H₂O₂) and nitrite ion (<inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" name="1752-153X-5-75-i1"><m:mrow><m:msubsup><m:mrow><m:mstyle class="text"><m:mtext>NO</m:mtext></m:mstyle></m:mrow><m:mrow><m:mn>2</m:mn></m:mrow><m:mrow><m:mo class="MathClass-bin">-</m:mo></m:mrow></m:msubsup></m:mrow></m:math></inline-formula>) is of great important in various fields including clinic, food, pharmaceutical and environmental analyses. Compared with many methods that have been developed for the determination of them, the electrochemical detection method has attracted much attention. In recent years, with the development of nanotechnology, many kinds of micro/nano-scale materials have been used in the construction of electrochemical biosensors because of their unique and particular properties. Among these catalysts, copper oxide (CuO), as a well known p-type semiconductor, has gained increasing attention not only for its unique properties but also for its applications in many fields such as gas sensors, photocatalyst and electrochemistry sensors. Continuing our previous investigations on transition-metal oxide including cuprous oxide and α-Fe₂O₃modified electrode, in the present paper we examine the electrochemical and electrocatalytical behavior of flower like copper oxide modified glass carbon electrodes (CuO/GCE).</p> <p>Results</p> <p>Flower like copper oxide (CuO) composed of many nanoflake was synthesized by a simple hydrothermal reaction and characterized using field-emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD). CuO modified glass carbon electrode (CuO/GCE) was fabricated and characterized electrochemically. A highly sensitive method for the rapid amperometric detection of hydrogen peroxide (H₂O₂) and nitrite (<inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" name="1752-153X-5-75-i1"><m:mrow><m:msubsup><m:mrow><m:mstyle class="text"><m:mtext>NO</m:mtext></m:mstyle></m:mrow><m:mrow><m:mn>2</m:mn></m:mrow><m:mrow><m:mo class="MathClass-bin">-</m:mo></m:mrow></m:msubsup></m:mrow></m:math></inline-formula>) was reported.</p> <p>Conclusions</p> <p>Due to the large specific surface area and inner characteristic of the flower like CuO, the resulting electrode show excellent electrocatalytic reduction for H₂O₂and oxidation of <inline-formula><m:math xmlns:m="http://www.w3.org/1998/Math/MathML" name="1752-153X-5-75-i1"><m:mrow><m:msubsup><m:mrow><m:mstyle class="text"><m:mtext>NO</m:mtext></m:mstyle></m:mrow><m:mrow><m:mn>2</m:mn></m:mrow><m:mrow><m:mo class="MathClass-bin">-</m:mo></m:mrow></m:msubsup></m:mrow></m:math></inline-formula>. Its sensitivity, low detection limit, fast response time and simplicity are satisfactory. Furthermore, this synthetic approach can also be applied for the synthesis of other inorganic oxides with improved performances and they can also be extended to construct other micro/nano-structured functional surfaces.</p