Stable oligonucleotide-functionalized gold nanosensors for environmental biocontaminant monitoring
Maria V. Riquelme , Weinan Leng , Marcos Carzolio , Amy Pruden , Peter Vikesland
DOI:10.1016/j.jes.2017.08.005
Received April 09, 2017,Revised August 07, 2017, Accepted August 08, 2017, Available online August 12, 2017
Volume 29,2017,Pages 49-59
The global propagation of environmental biocontaminants such as antibiotic resistant
pathogens and their antibiotic resistance genes (ARGs) is a public health concern that
highlights the need for improved monitoring strategies. Here, we demonstrate the
environmental stability and applicability of an oligonucleotide-functionalized gold
nanosensor. The mecA ARG was targeted as model biocontaminant due to its presence
in clinically-relevant pathogens and to its emergence as an environmental contaminant.
mecA-specific nanosensors were tested for antibiotic resistance gene (ARG) detection in
ARG-spiked effluent from four wastewater treatment plants (WWTPs). The mecA-specific
nanosensors showed stability in environmental conditions and in high ionic strength
([MgCl2] < 50 mM), and high selectivity against mismatched targets. Spectrophotometric
detection was reproducible with an LOD of 70 pM (≈4 × 107 genes/μL), even in the
presence of interferences associated with non-target genomic DNA and complex WWTP
effluent. This contribution supports the environmental applicability of a new line of
cost-effective, field-deployable tools needed for wide-scale biocontaminant monitoring.
