Review of micro/nanotechnologies for microbial biosensors

Abstract

A microbial biosensor is an analytical device with a biologically integrated transducer that generates a measurable signal indicating the analyte concentration. This method is ideally suited for the analysis of extracellular chemicals and the environment, and for metabolic sensory regulation. Although microbial biosensors show promise for application in various detection fields, some limitations still remain such as poor selectivity, low sensitivity, and impractical portability. To overcome such limitations, microbial biosensors have been integrated with many recently developed micro/nanotechnologies and applied to a wide range of detection purposes. This review article discusses micro/nanotechnologies that have been integrated with microbial biosensors and summarizes recent advances and the applications achieved through such novel integration. Future perspectives on the combination of micro/nanotechnologies and microbial biosensors will be discussed, and the necessary developments and improvements will be strategically deliberated.

Keywords: bioreactor; micro/nanomaterials; micro/nanotechnology; microbial biosensor; microfluidics; riboswitch; sensory-regulative biosensor.

Figure 1

Schematic diagram represents (A) micro/nanotechnolgies enhancing the performance of microbial biosensors, (B) limitations of conventional microbial biosensors, and (C) general features of biosensors.

Figure 2

Various micro/nanotechnologies for enhancing the performance of microbial biosensors. (A) A magnetotacic array device was introduced that can improve the positioning of microbial biosensor by separating a detection area from a cultivation area. The figure is reprinted with the permission from Roda et al. (2013) [Copyright (2013) Royal Society of Chemistry]. (B) A microfluidic device was developed for multiplex detection of small volume samples (Kim et al., 2014). The image is reproduced with the permission from Kim et al. [Copyright (2015) Elsevier B. V.]. (C) Miniaturized bioreactor facilitates not only the cultivation of bacterial cells but also the real-time monitoring of toxic material at a practical level. The image is reprinted with the permission from Thouand et al. (2003) [Copyright (2003) Springer International Publishing AG]. (D) A removable multi-well card was introduced for automated detection of multiple components. The image is reprinted with the permission from Charrier et al. (2011) [Copyright (2003) Springer International Publishing AG].

Figure 3

Novel micro/nanoscale structures and materials for enhancing the performance of electrochemical detection of microbial biosensors. (A) A miniaturized microbial biosensor was integrated with eight electrochemical sensing cells fabricated by photolithography techniques. Toxic materials such as phenol and ethanol in water were detected in a high-throughput manner. The figure is reproduced with the permission from Popovtzer et al. (2005) [Copyright (2005) American Chemical Society]. (B) A microfluidic device enabled microbial biosensors to conduct quantitative analysis and live monitoring of AQDS. Laminar flows generated by a Y-shape microfluidic channel network made it possible to reduce reaction and response time in electrochemical detection. The figure is reproduced with the permission from Li et al. (2012) [Copyright (2012) John Wiley and Sons, Inc.]. (C) Electrodes were fabricated by using microfabrication techniques including deep reactive ion etching and then applied to microbial biosensors. Since the microstructured electrodes enhanced electric signal from microbial biosensors, the induction factor improved over two times. The figure is reproduced with the permission from Ben-Yoav et al. (2012) [Copyright (2012) Elsevier B. V.]. (D) Metallic nanoparticles integrated with silk microfibers showed remarkable sensing ability for the detection of glucose in various concentrations. The figure is reproduced with the permission from Deng et al. (2010) [Copyright (2010) Elsevier B. V.].