Laser ablated ZnO thin film for amperometric detection of urea

Abstract

Zinc oxide (ZnO) thin films deposited onto indium tin oxide (ITO) coated corning glass substrates using pulsed laser deposition (PLD) technique at two different oxygen pressures (50 mT and 100 mT) have been used as efficient matrix for realization of efficient urea biosensors after immobilization of urease (Urs) enzyme onto ZnO film surface. The bioelectrode Urs/ZnO/ITO/glass having ZnO matrix grown at 100 mT is found to be exhibiting an enhanced sensitivity of 36 μΑ mΜ−1 cm−2 for urea over a wide detection range of 5–200 mg/dl. The relatively low value of Michaelis–Menten constant (Km = 0.82 mM) indicates high affinity of the immobilized urease towards the analyte (urea). The prepared sensor exhibits high selectivity towards detection of urea and retains 90% of its activity for more than 12 weeks. The observed enhanced response characteristics of bioelectrode is attributed to the growth of highly c-axis oriented ZnO thin film by PLD at 100 mT oxygen pressure with desired rough and porous surface morphology besides high electron communication feature. The results confirm the promising application of PLD grown ZnO thin film as an efficient matrix for urea detection.

Urea impedimetric biosensor based on reactive RF magnetron sputtered zinc oxide nanoporous transducer

“…Potentiometric biosensors based on Urs have been the most preferred choice due to simple mode of detection based on either detection of ammonium ions or pH change. The high potassium ion interference is the major disadvantage of these electrodes [26][27][28]. Besides, several attempts have been done for development of urea determination based on amperometric methods due to its effectiveness, simplicity, ease of calibration, etc [29][30][31].…”

Disposable urea biosensor based on nanoporous ZnO film fabricated from omissible polymeric substrate

“…9 C, showed a maximum interference of 2.1% with the presence of ascorbic acid. The results illustrated the importance of the prepared biosensor (FTO/ZnO/Urs) in the selective detection of urea.Finally, based on the enzyme electrostatic immobilization strategy, the response characteristics of the FTO/ZnO/Urs biosensor with the other reported urea biosensors was compared and summarized inTable 2[45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63]. We are currently developing nanostructured ZnO based urea biosensing using impedimetric assessment.…”

Influence of stress in ZnO thin films on its biosensing application

“…Metal-insulator-metal (MIM) structure with platinum (Pt) as the top and bottom electrodes was used for electrical studies as has been discussed elsewhere [19]. The cyclic voltammetry is the technique being used by the research community for bio-electroanalysis of the electrochemical biosensors [9,13,19,23]. Cyclic voltammetry (Gamry potentiostat/galvanostat Reference 300 model) was employed for electrochemical and biosensing response studies.…”

“…However, the recent interdisciplinary research in the field of ZnO has led to the rapid development of a number of ZnO based biosensors [9][10][11][12]. The high electron communication feature of ZnO and its * Corresponding author.…”

“…ZnO has found a wide range of applications [3][4][5][6][7][8][9][10]. However, the recent interdisciplinary research in the field of ZnO has led to the rapid development of a number of ZnO based biosensors [9][10][11][12].…”