A Hierarchical 3D Nanostructured Microfluidic Device for Sensitive Detection of Pathogenic Bacteria

Abstract

Efficient capture and rapid detection of pathogenic bacteria from body fluids lead to early diagnostics of bacterial infections and significantly enhance the survival rate. We propose a universal nano/microfluidic device integrated with a 3D nanostructured detection platform for sensitive and quantifiable detection of pathogenic bacteria. Surface characterization of the nanostructured detection platform confirms a uniform distribution of hierarchical 3D nano-/microisland (NMI) structures with spatial orientation and nanorough protrusions. The hierarchical 3D NMI is the unique characteristic of the integrated device, which enables enhanced capture and quantifiable detection of bacteria via both a probe-free and immunoaffinity detection method. As a proof of principle, we demonstrate probe-free capture of pathogenic Escherichia coli (E. coli) and immunocapture of methicillin-resistant-Staphylococcus aureus (MRSA). Our device demonstrates a linear range between 50 and 10 CFU mL , with average efficiency of 93% and 85% for probe-free detection of E. coli and immunoaffinity detection of MRSA, respectively. It is successfully demonstrated that the spatial orientation of 3D NMIs contributes in quantifiable detection of fluorescently labeled bacteria, while the nanorough protrusions contribute in probe-free capture of bacteria. The ease of fabrication, integration, and implementation can inspire future point-of-care devices based on nanomaterial interfaces for sensitive and high-throughput optical detection.

Interactions of Bacteria With Monolithic Lateral Silicon Nanospikes Inside a Microfluidic Channel

“…Lab-on-a-chip (LOC) technology, which features microchannels and microstructures with dimensions ranging from a micron to a few 100 microns, has offered tremendous benefits for the research of mammalian cells since early 1990s. In recent years, increasing numbers and varieties of LOC devices have been used for bacteria study, such as capture (Guo et al, 2012), separation (Beech et al, 2018), and detection (Jalali et al, 2018). However, since the size of bacteria is usually about one micron and the widely used ultra-violet (UV) light lithography for LOC fabrication cannot produce structures below one micron due to diffraction limit, the performance of LOC systems for bacterial research have not reached the same level with mammalian cells.…”

In Situ Shape Control of Thermoplasmonic Gold Nanostars on Oxide Substrates for Hyperthermia-Mediated Cell Detachment

“…This strategy enables us to integrate the plasmonic structures with more complex substrate geometries, such as glass tubing and microfluidic capillaries, which are of great interest for the development of sensors and devices probing biological systems. 44 By translating optimized parameters for colloidal synthesis to substrate-mediated growth, we achieved uniform AuNST coatings on indium tin oxide (ITO) ( Figure 1 B), glass slides ( Figure 1 C), and along the internal walls of glass microcapillaries ( Figure 1 D,E). The final products yield films that appear blue in color with a broad LSPR peak at ca .…”

Nanostructured Architectures for Biomolecular Detection inside and outside the Cell

“…[154] Other groups have also demonstrated the benefits of tuning the nanostructure architecture of electrodes to regulate detection sensitivity. [155,156] Gold-based NMEs have been adapted for widespread use in biosensing from the detection of the small molecule dopamine [157] to detecting whole bacterial cells [158] and even at the single-cell level in eukaryotes. [91] They have also been shown to perform well in biological samples such as blood, [159] urine, [160] and bacterial lysates.…”