Whole-Cell Pseudomonas aeruginosa Localized Surface Plasmon Resonance Aptasensor

Abstract

The detection of whole-cell Pseudomonas aeruginosa presents an intriguing challenge with direct applications in health care and the prevention of nosocomial infection. To address this problem, a localized surface plasmon resonance (LSPR) based sensing platform was developed to detect whole-cell Pseudomonas aeruginosa strain PAO1 using a surface-confined aptamer as an affinity reagent. Nanosphere lithography (NSL) was used to fabricate a sensor surface containing a hexagonal array of Au nanotriangles. The sensor surface was subsequently modified with biotinylated polyethylene glycol (Bt-PEG) thiol/PEG thiol (1:3), neutravidin, and biotinylated aptamer in a sandwich format. The 1:3 (v/v) ratio of Bt-PEG thiol/PEG thiol was specifically chosen to maximize PAO1 binding while minimizing nonspecific adsorption and steric hindrance. In contrast to prior whole-cell LSPR work, the LSPR wavelength shift was shown to be linearly related to bacterial concentration over the range of 10–103 cfu mL−1. This LSPR sensing platform is rapid (~3 h for detection), sensitive (down to the level of a single bacterium), selective for detection of Pseudomonas strain PAO1 over other strains, and exhibits a clinically relevant dynamic range and excellent shelf life (≥2 months) when stored at ambient conditions. This versatile LSPR sensing platform should be extendable to a wide range of supermolecular analytes, including both bacteria and viruses, by switching affinity reagents, and it has potential to be used in point-of-care and field-based applications.

Nanomaterial enabled sensors for environmental contaminants

“…Most of the detection schemes reported for P. aeruginosa focus on whole pathogen detection [ 142 – 146 ] with the work of Melanie et al [ 139 ], discussed above, on 16s rRNA detection being an outlier. In addition, to oligonucleotide recognition elements [ 139 , 142 – 144 ], antibodies [ 145 , 147 ] and bacteriophages [ 146 ] have also been used for specific detection of P. aeruginosa .…”

“…The discussion that follows highlights two sensors that utilize optical transduction. Yoo et al [ 142 ] and Hu et al [ 144 ] fabricated nano-textured substrates to produce localized surface plasmon resonance (LSPR) chips (Fig. 7 ).…”

“…Sensor calibration curve, where error bar represents the standard deviation of all data points at a specific bacterial concentration (right). (Reprinted with permission from Hu et al [ 144 ]. Copyright 2018 American Chemical Society) …”

A Fluorescent Sensor Based on Reversible Addition-Fragmentation Chain Transfer Polymerization for the Early Diagnosis of Non-small Cell Lung Cancer

“…[10][11][12][13] The remarkable flexibility in sensor design is reflected by its interdisciplinary nature combining with electrochemistry, quartz crystal microbalance (QCM), electroluminescence, fluorescence, surface plasmon resonance (SPR) and other technologies. [14][15][16][17] Especially, the fluorescent sensors are gaining great attention by virtue of their high sensitivity, non-destructive nature, rapid, and the ability for real-time monitoring.…”

Microscale and Nanoscale Electrophotonic Diagnostic Devices

“…A broad range of recognition agents include: biotin and (strept/neutr)avidin (Haes and Van Duyne 2002), antibody-antigen pairs (Hall et al 2011b), lectin and carbohydrates (Cai et al 2017), enzyme-substrate pairs (Sekretaryova et al 2014), siderophores (Doorneweerd et al 2010), bacteriophages (Tripathi et al 2012), as well as oligonucleotide-based recognition systems, such as aptamers (Urmann et al 2016), antimicrobial peptides (Mannoor et al 2010), and other DNA sequences. These recognition agents are used to target small molecules (Muguruma et al 2011), proteins (Bertok et al 2013), bacterial lysates (Taylor et al 2006), bacterial spores (Pestov et al 2008), intact bacterial cells (Hu et al 2018), viral proteins (Nidzworski et al 2017), viral DNAs (Dong et al 2015), and intact viruses (Chang et al 2018).…”