Copper nanowire array as highly selective electrochemical sensor of nitrate ions in water

Abstract

Contamination of water with nitrate ions is a significant problem that affects many areas of the world. The danger from nitrates is not so much their toxicity, rather low, as their transformation into nitrites and in particular into nitrosamines, substances considered to be a possible carcinogenic risk. For this reason, European legislation has set the maximum permissible concentration of nitrates in drinking water at 44 mg/l. Thus, it is clear that a continuous monitoring of nitrate ions is of high technological interest but it must be rapid, easy to perform and directly performable in situ. Electrochemical detection is certainly among the best techniques to obtain the above requirements. In particular, in this work we have developed a nanostructured sensor based on array of copper nanowires obtained with the simple method of galvanic deposition. The nanostructured sensors have a very short response time with a detection limit less than 10 M. Different interfering species were tested finding a negligible effect except for the chlorine ions. However, this problem has been solved by removing chlorine ions from the water through a simple precipitation of chloride compounds with low solubility. Nanostructured sensors were also used to analyze real water samples (rain, river and drinking water). In the case of drinking water, we have measured a concentration of nitrate ions very close to the that measured by conventional laboratory techniques.

Electrochemical Synthesis of Zinc Oxide Nanostructures on Flexible Substrate and Application as an Electrochemical Immunoglobulin-G Immunosensor

“…The ability to obtain ZnO in nanostructured form is extremely interesting because nanostructured morphology allows electrodes with higher surface area and thus higher reactivity to be fabricated [47]. These properties are of great importance in many applications, especially for batteries [48,49], electrolyzes [50][51][52], solar cells [53,54], magnetic devices [55,56] and sensors [57][58][59]. In this work we explored the possibility of using electrochemically obtained ZnO nanorods (ZnO-NRs) as a basis for the fabrication of immunosensors for human immunoglobulin G (H-IgG).…”

“…The development of new kinds of analytical devices able to carry out fast, accurate, and real time analysis in situ is of great importance in many different fields, from health [68][69][70][71], to sport [72][73][74], homecare and environment among others [58,73,[75][76][77][78][79]. Electrochemical immunosensors are perfect candidates to achieve this as they are cheap and portable.…”

PANI-Based Wearable Electrochemical Sensor for pH Sweat Monitoring

“…Among the different manufacturing methods, the electrochemical one appears extremely interesting because it is fast, easy to scale and simple. Furthermore, it allows obtaining different materials in different morphologies, successfully applicable and with excellent results in different electrochemical devices [49][50][51][52][53][54][55][56][57]. In particular, in the case of PANI, the electrodeposition method is very suitable because it permits controlling its physical-chemical characteristics [58][59][60][61].…”

Electrochemical Synthesis of Zinc Oxide Nanostructures on Flexible Substrate and Application as an Electrochemical Immunoglobulin-G Immunosensor

“…The oppertunity of obtaining ZnO in nanostructured form is extremely interesting because the nanostructured morphology allows electrodes with higher surface area and thus higher reactivity to be fabrciated. These properties are of great importance in many applications, especially for batteries [43,44], electrolyzes [45][46][47], solar cell [48,49], magnetic devices [50,51] and sensors [52][53][54][55]. In this work we explored the possibility of using electrochemically obtained ZnO nanorods (ZnO-NRs) as a basis for the fabrication of immunosensors for human immunoglobulin G (H-IgG).…”

“…The development of new kinds of analytical devices to able to carry out fast, accurate, and real time analysis in situ is of great importance in many different fields, from health [72][73][74][75][76], to sport [77,78], homecare and environment among others [54,[78][79][80][81][82]. Electrochemical immunosensors are perfect candidates to achieve this as they are cheap and portable.…”