Recent trends in rapid environmental monitoring of pathogens and toxicants: potential of nanoparticle-based biosensor and applications

Abstract

Of global concern, environmental pollution adversely affects human health and socioeconomic development. The presence of environmental contaminants, especially bacterial, viral, and parasitic pathogens and their toxins as well as chemical substances, poses serious public health concerns. Nanoparticle-based biosensors are considered as potential tools for rapid, specific, and highly sensitive detection of the analyte of interest (both biotic and abiotic contaminants). In particular, there are several limitations of conventional detection methods for water-borne pathogens due to low concentrations and interference with various enzymatic inhibitors in the environmental samples. The increase of cells to detection levels requires long incubation time. This review describes current state of biosensor nanotechnology, the advantage over conventional detection methods, and the challenges due to testing of environmental samples. The major approach is to use nanoparticles as signal reporter to increase output rather than spending time to increase cell concentrations. Trends in future development of novel detection devices and their advantages over other environmental monitoring methodologies are also discussed.

Figure 1

Schematic diagram illustrating different nanoparticles conferring optical (e.g., gold nanoparticles (GNPs)), fluorescence (e.g., quantum dots (QDs)), and magnetic (e.g., magnetic nanoparticles (MNPs)) properties, and combinations between these particles as nanocomposites conferring multifunctionalities provide distinct advantages for environmental monitoring.

Figure 2

Scheme representing nanobiosensor components consisting of different bioreceptors (e.g., antibodies, aptamers, cell-surface molecules, enzymes, oligonucleotide probes, and phages) and major transducers depending on types of signal response (i.e., optical, electrochemical, and mechanical signal). Output can be displayed as UV-visible or photoluminescence spectra and magnetic resonance images.

Figure 3

Scheme depicting principle of biosensor-based detection using (a) gold nanoparticles and (b) quantum dots as well as (c) magnetic nanoparticle aggregates for detection of microcystin-LR (MC-LR), naturally occurring toxin produced from cyanobacteria.

Figure 4

Common procedures for detection of certain water-borne pathogens in environmental matrices and progressive development of respective bionanosensors including immunosensor, DNA-based sensor, and others. Irrespectively, preprocessing steps of necessity initially require filtration and concentration, and then an immunoseparation step (e.g., immunomagnetic separation) in several types of assays.