A review study of (bio)sensor systems based on conducting polymers.

Rapid diagnosis of infectious diseases and timely initiation of appropriate treatment are critical determinants that promote optimal clinical outcomes and general public health Conventional in vitro diagnostics for infectious diseases are time-consuming and require centralized laboratories, experienced personnel and bulky equipment Recent advances in biosensor technologies have potential to deliver point-of-care diagnostics that match or surpass conventional standards in regards to time, accuracy and cost Broadly classified as either label-free or labeled, modern biosensors exploit micro- and nanofabrication technologies and diverse sensing strategies including optical, electrical and mechanical transducers Despite clinical need, translation of biosensors from research laboratories to clinical applications has remained limited to a few notable examples, such as the glucose sensor Challenges to be overcome include sample preparation, matrix effects and system integration We review the advances of biosensors for infectious disease diagnostics and discuss the critical challenges that need to be overcome in order to implement integrated diagnostic biosensors in real world settings

https://web.stanford.edu/group/liaolab/Publications/2014/Advances%20and%20challenges%20in%20biosensor-based%20diagnosis%20of%20infectious%20diseases.pdf

Advances and challenges in biosensor-based diagnosis of infectious diseases

Rapid detection of bacterial pathogens and toxins in foods is necessary to provide real-time results to mitigate foodborne illness outbreaks. Cultural enrichment methods, although the most widely used, are time-consuming and therefore inadequate for rapid pathogen detection from food samples. The development of novel "rapid" detection methods has decreased detection time dramatically. This review presents an overview of detection methods for various foodborne pathogens, including Listeria monocytogenes, Salmonella enterica, and shiga toxin-producing Escherichia coli, and bacterial toxins in food matrices, with emphasis on those methods which do not require cultural enrichment. Discussed methods include nucleic acid-, immunological-, and biosensor-based techniques. A summary of each type of detection method is given, including referenced methods from the literature. Since these discussed methods do not require cultural enrichment, there is a higher probability of interference from the food matrices. Therefore, the review also discusses the potential interference of food components on detection methods and addresses preprocessing strategies to overcome matrix associated inhibition and to concentrate low quantities of pathogens and toxins in food. Development of rapid and sensitive detection technologies advances and ensures public health safety and security.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/1541-4337.12175

Culture‐Independent Rapid Detection Methods for Bacterial Pathogens and Toxins in Food Matrices

The accurate detection of biological materials has remained at the forefront of scientific research for decades. This includes the detection of molecules, proteins, and bacteria. Biomimetic sensors look to replicate the sensitive and selective mechanisms that are found in biological systems and incorporate these properties into functional sensing platforms. Molecularly imprinted polymers (MIPs) are synthetic receptors that can form high affinity binding sites complementary to the specific analyte of interest. They utilise the shape, size, and functionality to produce sensitive and selective recognition of target analytes. One route of synthesizing MIPs is through electropolymerization, utilising predominantly constant potential methods or cyclic voltammetry. This methodology allows for the formation of a polymer directly onto the surface of a transducer. The thickness, morphology, and topography of the films can be manipulated specifically for each template. Recently, numerous reviews have been published in the production and sensing applications of MIPs; however, there are few reports on the use of electrosynthesized MIPs (eMIPs). The number of publications and citations utilising eMIPs is increasing each year, with a review produced on the topic in 2012. This review will primarily focus on advancements from 2012 in the use of eMIPs in sensing platforms for the detection of biologically relevant materials, including the development of increased polymer layer dimensions for whole bacteria detection and the use of mixed monomer compositions to increase selectivity toward analytes.

https://www.mdpi.com/1424-8220/19/5/1204/pdf

Recent Advances in Electrosynthesized Molecularly Imprinted Polymer Sensing Platforms for Bioanalyte Detection

Molecularly Imprinted Polymers for Cell Recognition

Specific identification of bacteria has been achieved through precisely transferred bacterial structure on the surface of overoxidized polypyrrole (OPPy) film. The recognition of target bacteria was successfully carried out in real time using OPPy film in combination with dielectrophoresis. The unique combination of both techniques made the specific detection of template bacilli possible at concentrations as low as 103 CFU/mL within 3 min, without any bacterial pretreatment. The observation of the movement of bacteria by using a fluorescent microscope revealed that living bacteria were being trapped vertically in the cavity created in the OPPy film. Further, the bacterial cavities had high selectivity and were able to discriminate particular target bacteria, Pseudomonas aeruginosa, out of bacterial mixtures containing Acinetobacter calcoaceticus, Escherichia coli, and Serratia marcescens, which are known to have a similar shape. This simple method can be used for a wide variety of applications in which ra...

Label-Free and Selective Bacteria Detection Using a Film with Transferred Bacterial Configuration

We have successfully developed a novel technique for inserting viable bacilliform bacteria into polypyrrole films. All of the five different bacterial cells (Pseudomonas aeruginosa, Acinetobacter calcoaceticus, Serratia marcescens, Bacillus subtilis and Escherichia coli) studied in this work were inserted normal to the film surface, and the viability of P. aeruginosa was unaffected by this immobilization procedure. It was also found that the polypyrrole layer was important to keep the cells alive.

https://www.jstage.jst.go.jp/article/analsci/28/4/28_4_319/_pdf

Kenta Saimatsu

Papers

Label-Free and Selective Bacteria Detection Using a Film with Transferred Bacterial Configuration

Vertical immobilization of viable bacilliform bacteria into polypyrrole films.