Detection of chemical and biological agents plays a fundamental role in biomedical, forensic and environmental sciences1–4 as well as in anti bioterrorism applications.5–7 The development of highly sensitive, cost effective, miniature sensors is therefore in high demand which requires advanced technology coupled with fundamental knowledge in chemistry, biology and material sciences.8–13

In general, sensors feature two functional components: a recognition element to provide selective/specific binding with the target analytes and a transducer component for signaling the binding event. An efficient sensor relies heavily on these two essential components for the recognition process in terms of response time, signal to noise (S/N) ratio, selectivity and limits of detection (LOD).14,15 Therefore, designing sensors with higher efficacy depends on the development of novel materials to improve both the recognition and transduction processes. Nanomaterials feature unique physicochemical properties that can be of great utility in creating new recognition and transduction processes for chemical and biological sensors15–27 as well as improving the S/N ratio by miniaturization of the sensor elements.28

Gold nanoparticles (AuNPs) possess distinct physical and chemical attributes that make them excellent scaffolds for the fabrication of novel chemical and biological sensors (Figure 1).29–36 First, AuNPs can be synthesized in a straightforward manner and can be made highly stable. Second, they possess unique optoelectronic properties. Third, they provide high surface-to-volume ratio with excellent biocompatibility using appropriate ligands.30 Fourth, these properties of AuNPs can be readily tuned varying their size, shape and the surrounding chemical environment. For example, the binding event between recognition element and the analyte can alter physicochemical properties of transducer AuNPs, such as plasmon resonance absorption, conductivity, redox behavior, etc. that in turn can generate a detectable response signal. Finally, AuNPs offer a suitable platform for multi-functionalization with a wide range of organic or biological ligands for the selective binding and detection of small molecules and biological targets.30–32,36 Each of these attributes of AuNPs has allowed researchers to develop novel sensing strategies with improved sensitivity, stability and selectivity. In the last decade of research, the advent of AuNP as a sensory element provided us a broad spectrum of innovative approaches for the detection of metal ions, small molecules, proteins, nucleic acids, malignant cells, etc. in a rapid and efficient manner.37



Figure 1

Physical properties of AuNPs and schematic illustration of an AuNP-based detection system.



In this current review, we have highlighted the several synthetic routes and properties of AuNPs that make them excellent probes for different sensing strategies. Furthermore, we will discuss various sensing strategies and major advances in the last two decades of research utilizing AuNPs in the detection of variety of target analytes including metal ions, organic molecules, proteins, nucleic acids, and microorganisms.

/pdf/gold-nanoparticles-in-chemical-and-biological-sensing-5e2qojkdzn.pdf

Gold nanoparticles in chemical and biological sensing.

This critical review provides an overall survey of the basic concepts and up-to-date literature results concerning the very promising use of gold nanoparticles (AuNPs) for medicinal applications. It includes AuNP synthesis, assembly and conjugation with biological and biocompatible ligands, plasmon-based labeling and imaging, optical and electrochemical sensing, diagnostics, therapy (drug vectorization and DNA/gene delivery) for various diseases, in particular cancer (also Alzheimer, HIV, hepatitis, tuberculosis, arthritis, diabetes) and the essential in vitro and in vivo toxicity. It will interest the medicine, chemistry, spectroscopy, biochemistry, biophysics and nanoscience communities (211 references).

Gold nanoparticles in nanomedicine: preparations, imaging, diagnostics, therapies and toxicity

Phenolics and polyphenolics in foods, beverages and spices: Antioxidant activity and health effects – A review

Considered by some to be among the simpler forms of life, viruses represent highly evolved natural vectors for the transfer of foreign genetic information into cells. This attribute has led to extensive attempts to engineer recombinant viral vectors for the delivery of therapeutic genes into diseased tissues. While substantial progress has been made, and some clinical successes are over the horizon, further vector refinement and/or development is required before gene therapy will become standard care for any individual disorder.

/pdf/viral-vectors-for-gene-therapy-the-art-of-turning-infectious-3minu6de1n.pdf

Viral vectors for gene therapy: the art of turning infectious agents into vehicles of therapeutics

An overview of foodborne pathogen detection: In the perspective of biosensors

http://ssu.ac.ir/cms/fileadmin/user_upload/Mtahghighat/tfood/ARTICLES/microb-safety/A_review_of_microbial_injury_and_recovery_methods_in_food.pdf

A review of microbial injury and recovery methods in food.

Antimicrobial action of the American cranberry constituents; phenolics, anthocyanins, and organic acids, against Escherichia coli O157:H7

Antibacterial effects of American cranberry ( Vaccinium macrocarpon ) concentrate on foodborne pathogens, Escherichia coli O157:H7, Listeria monocytogenes , Salmonella Typhimurium, and Staphylococcus aureus in vitro were investigated Cranberry concentrate at various concentrations was prepared in distilled water (DW) or Brain Heart Infusion (BHI) broth Pathogens were inoculated in each sample and incubated at 21 and 4 °C for 0, 1, 5, 7, and 24 h (DW samples) and 0, 1, 3, and 5 days (BHI samples) Transmission electron microscopy (TEM) was used to study the effects of cranberry concentrate on cellular structure of pathogens DW results showed that S Typhimurium and L monocytogenes were reduced to non-detectable levels at 5 h in 100 μl/ml treatment at 21 and 4 °C At 24 h, no target pathogens were detected from the 100 μl/ml treatment BHI data indicated that the 100 μl/ml treatment reduced the four pathogens by 3–8 log CFU/ml compared with the control on Day 5 at 21 and 4 °C TEM revealed damage to the bacterial cell walls and membranes Cranberry concentrate has antibacterial effects on the four foodborne pathogens Based on potential health benefits and proven antimicrobial effects, American cranberry concentrate may have dual applications as a food preservative

Antibacterial effects of American cranberry (Vaccinium macrocarpon) concentrate on foodborne pathogens

https://ir.nctu.edu.tw:443/bitstream/11536/9478/1/000255300600002.pdf

Vivian C.H. Wu

Papers

A review of microbial injury and recovery methods in food.

Antimicrobial action of the American cranberry constituents; phenolics, anthocyanins, and organic acids, against Escherichia coli O157:H7

Antibacterial effects of American cranberry (Vaccinium macrocarpon) concentrate on foodborne pathogens

Using oligonucleotide-functionalized Au nanoparticles to rapidly detect foodborne pathogens on a piezoelectric biosensor

Antibacterial effect and mechanism of anthocyanin rich Chinese wild blueberry extract on various foodborne pathogens