Dip-Pen Nanolithography Fabrication of Meta Chemical Surfaces for Heavy Metal Detection: The Role of PMMA in Enhancing Sensor Sensitivity

Moshe Zohar, Electrical and Electronics Engineering, Sami Shamoon College of Engineering, Beer-Sheva, Israel (moshezo@ac.sce.ac.il)
Dror Shamir, Analytical Chemistry, Nrcn, Beer-sheva, Israel
Haya Kornweitz, Chemical Sciences, Ariel University, Ariel, Israel
Ariela Burg, Chemical Engineering, Sami Shamoon College Of Engineering, Beer-sheva, Israel

Access to clean water is essential for life; yet, contamination from industrialization, agriculture, and environmental changes continues to pose a significant global challenge [1,2]. Heavy metals in groundwater often exceed the World Health Organization (WHO) limits, necessitating the use of advanced detection technologies [3]. We present novel electrochemical sensors based on meta-chemical surfaces (MCS) fabricated via dip-pen nanolithography (DPN), a technique enabling precise nanoscale patterning [4-5]. Two sensor types were developed using PMMA-based inks functionalized with distinct ligands: 1,8-diaminonaphthalene (DAN) and D-penicillamine (D-PA). Their nanoscale architecture and high surface-to-volume ratios (18.6 µm⁻¹ for DAN and 23.1 µm⁻¹ for D-PA), combined with strong ligand–metal interactions (binding energies of −2.21 kcal/mol for DAN and −21.37 kcal/mol for D-PA), deliver exceptional sensitivity. This performance is reflected in detection limits of 0.40 ppb (DAN) and 0.30 ppb (D-PA). Density Functional Theory (DFT) calculations confirm that the incorporation of PMMA enhances ligand–metal binding, underscoring its critical role in sensor optimization. These findings highlight PMMA-assisted DPN as a promising route for next-generation heavy metal sensors.

 

Short Biography of Presenting Author

Moshe Zohar is a senior lecturer and researcher in the Department of Electrical and Electronics Engineering at Sami Shamoon College of Engineering (SCE), Israel. His work focuses on dip-pen nanolithography for the fabrication of advanced sensors, with expertise in developing optical detectors across the electromagnetic spectrum and electrochemical sensors. He has extensive experience integrating polymers into device design and applying simulation and optimization techniques to enhance performance. His research interests include nanoscale optical gratings, electrochemical sensing, photodetectors, optoelectronics, and light-management strategies for energy-harvesting applications.