Thomas Schalkhammer

Nickel’s durability and catalytic properties make it essential in the aerospace, automotive, electronics, and fuel cell technology industries. Wastewater analysis typically relies on sensitive but costly techniques such as ICP-MS, AAS, and ICP-AES, which require complex equipment and are unsuitable for on-site testing. This study introduces a novel screen-printed electrode array with 16 chemically and, optionally, electrochemically coated Au electrodes. Its electrochemical response to Ni²⁺ was tested using Na₂SO₃ and ChCl-EG deep eutectic solvents as electrolytes. Ni²⁺ solutions were prepared from NiCl₂·6H₂O, NiSO₄·6H₂O, and dry NiCl₂. In Na₂SO₃, the linear detection ranges were 20–196 mM for NiCl₂·6H₂O and 89–329 mM for NiSO₄·6H₂O. High Ni²⁺ concentrations (10–500 mM) were used to simulate industrial conditions. Two linear ranges were observed, likely due to differences in electrochemical behaviour between NiCl₂·6H₂O and NiSO₄·6H₂O, despite the identical Na₂SO₃ electrolyte. Anion effects (Cl⁻ vs. SO₄²⁻) may influence response via complexation or ion pairing. In ChCl-EG, a linear range of 0.5–10 mM (R² = 0.9995) and a detection limit of 1.6 µM were achieved. With a small electrolyte volume (100–200 µL), nickel detection in the nanomole range is possible. A key advantage is the array’s ability to analyze multiple analytes simultaneously via customizable electrode configurations. Future research will focus on nickel detection in industrial wastewater and its potential in the multiplexed analysis of toxic metals. The array also holds promise for medical diagnostics and food safety applications using thiol/Au-based capture molecules.

Within the last decade the use of nano‐structured polymers for biochips, biosensors and novel nano‐optical devices gained world‐wide attention due to a number of key‐developments. The most fascinating example is microelectronics, where smaller means more cost efficiency, more circuits per chip, faster, and less heat to dissipate. Many intriguing new phenomena occur at nanometer dimensions including quantum size effects, Coulomb blockade, plasmon wave guides and electron tunnelling.Defined multilayer nano‐assemblies enable to construct three‐dimensional devices based on Plasmon and nano‐optic resonance. Decisive for these types of devices and sensors is the ultra‐precise nanometric assembly. Manufacturing of opto‐nano‐devices thus requires the development of a completely new set of ultra‐precise techniques to deposit, arrange, and couple nano‐polymer layers. These nano‐layers are the most essential key elements of novel nano‐optical‐devices. Smart‐responsive nano‐polymer gels as transducer and building blocks for nano‐devices open novel routes to photonic nano‐optical sensors and chips. Optical effects based on ‘resonance enhanced absorption (REA)’ in combination with nano‐layers of smart‐stimulus‐response polymers allow the construction of a new type of sensor device.The article will focus on up‐to‐date lithographic techniques of nanolayers, continue to smart‐nanolayer polymers, describe the REA effect and lead to a functional REA‐polymer‐sensor.