Co, Ni, Cu, Zn, Hg) and metalloids from group 13-16 of the periodic table (e.g., Al, Ga, As, Sn, Sb, Pb, Bi) have increasingly Copper (Cu) and its alloys have been shown to eradicate a wide range of multidrug-resistant microbes upon direct contact. In this study, a facile one-step laser texturing (LT) process is demonstrated to effectively enhance the bactericidal properties of copper surfaces via concurrent selective modification of surface topography and chemistry of laser textured copper (LT-Cu). Surface morphology and elemental composition are analyzed via field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), and Raman spectroscopy. Surface area and pore size of LT-Cu is determined by Barrett-Joyner-Halenda (BJH) and Brunauer-Emmett-Teller (BET) analysis. It reveals direct formation of mesoporous structures with higher surface oxide (Cu 2 O and CuO), which provide a highly stable superhydrophilic property to the LT-Cu surfaces. The antibacterial properties of LT-Cu are tested against pathogenic bacterial strains with different concentrations including Pseudomonas aeruginosa, and methicillinresistant Staphylococcus aureus (MRSA USA300) at 10 5 CFU mL −1 , and Escherichia coli and Staphylococcus aureus at high bacterial concentrations of 10 8 CFU mL −1 using standard contact killing tests. The analysis shows that LT-Cu needs 40, 90, 60, and 120 min to completely eradicate the respective bacterial strain. The LT-Cu causes membrane damage to the bacterial cells immediately after exposure. Furthermore, the biocompatibility of LT-Cu is investigated by in vitro immune-staining assays with mammary stromal fibroblasts and T4-2 cells.

In this paper, we present a novel laser-induced oxidation procedure for in situ formation of nickel oxide nanoporous structures directly onto the nickel surface as a highly sensitive nonenzymatic glucose sensor. The formation of mesoporous nickel oxide is confirmed by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray diffraction. Electrochemical properties of the pristine and laser-induced oxidized nickel (LIO-Ni) films were studied using cyclic voltammetry and electrochemical impedance spectroscopy. The unique three-dimensional mesoporous architecture of the oxide film on the LIO-Ni electrode resulted in a dramatic enhancement in electrochemical reduction/oxidation performance with a 10-fold increase in electrocatalytic activity for nonenzymatic glucose oxidation as compared to the pristine-Ni electrode. The LIO-Ni biosensor performance was successfully examined for the amperometric detection of glucose over a wide concentration range from 5 μM to 1.1 mM with a high linear sensitivity of 5222 μA mM −1 cm −2 . The limit of detection was obtained as low as 3.31 μM with a signal-tonoise ratio of 3. Furthermore, the LIO-Ni electrode showed outstanding long-term stability, reproducibility, and high selectivity in the presence of various interfering agents including uric acid, L-ascorbic acid, acetaminophen, glutamic acid, and citric acid. The demonstrated laser-induced oxidation process can be potentially adapted to the scalable manufacturing of a wide range of other easyto-use and robust metal oxide-based sensors for nonenzymatic biosensing applications.

This work describes the preparation, characterization and use of a nickel oxide/oxyhydroxide-printed carbon electrode as an efficient potentiometric phosphate sensor.