His research melds metals and semiconductors with biological materials and could lead to a range of new products in medicine and manufacturing for tissue engineering, drug discovery, and computer chip fabrication.
“Nanotechnology is already saving lives, and will be crucial to the sustainability of life as we know it on Earth,” says Lenhert, whose work could lead to portable diagnostic devices built into mobile phones. He and his colleagues have recently used dip-pen nanolithography (DPN) to deposit biofunctional lipid multilayers with controllable heights between about 5 and 100 nanometres on a pre-structured surface with high resolution [Lenhert et al., Nature Nanotech (2010) 5, 275; doi: 10.1038/nnano.2010.17]
Lenhert originally developed his approach to DPN, which uses atomic force microscopy, at his former institutions, Germany's University of Muenster and Karlsruhe Institute of Technology and this work was carried out in collaboration with those teams. The development of the technique has now led to a fundamentally new class of material – biometamaterials, a substance constructed from biological molecules that that doesn't actually exist in nature. Such materials have many promising biological applications, such as colour-coded detection of various molecules through diffraction of light.
Lenhert's team explain that, “Multiple materials can be simultaneously written into arbitrary patterns on pre-structured surfaces to generate complex structures and devices.” This top-down approach to fabrication was exploited in creating a biocompatible lipid multilayer grating that can be used in label-free and specific detection of lipid-protein interactions in solution, the team says. This biosensor utilises the adhesion properties of the phospholipid superstructures and reveals the presence of an analyte binding to the surface as the physical characteristics of the grating elements change on binding.
“The challenge that lipid DPN allowed us to overcome is to make higher aspect ratio multilayer structures in a multiplexed printing process, to make functional gratings out of biological lipids that can efficiently diffract light,” adds Lenhert.
“The closest real-world application for this material is in medical diagnostics,” Lenhert explains. “The idea would be to have a portable, affordable and disposable chip that could allow your mobile phone to diagnose medical conditions that currently require a visit to a doctor and samples being sent to a laboratory.”
“The bottom-up fabrication method and unique biophysical properties of nano-structured lipid multilayers permits the integration of complex and dynamic biophotonic circuits,” the team concludes, “The technique will be useful for high-throughput biophysical analysis.”