Nanoparticle Enhanced Antibody and DNA Biosensors for Sensitive Detection of Salmonella

Abstract

Bacteria-related pathogenic diseases are one of the major health problems throughout the world. Salmonella is a genus of rod-shaped Gram-negative enterobacteria of which more than 2600 serotypes have been identified. Infection with Salmonella can cause salmonellosis, a serious bacterial toxi-infection syndrome associated with gastroenteritis, and paralyphoid and typhoid fevers. Its rapid and sensitive detection is a key to the prevention of problems related to health. This paper describes the development of antibody and DNA sensors for Salmonella detection using a microfluidic-based electrochemical system. Commercial Salmonella typhimurium and Salmonella typhimurium from human stool samples were investigated using standard and nanomaterial-amplified antibody sensors. S. typhimurium could be detected down to 1 cfu mL−1. The specificity of immunoassay was tested by studying with non-specific bacteria including E. coli and S. aureus that revealed only 2.01% and 2.66% binding when compared to the target bacterium. On the other hand, the quantification of Salmonella DNA was investigated in a concentration range of 0.002–200 µM using the developed DNA biosensor that demonstrated very high specificity and sensitivity with a detection limit of 0.94 nM. Our custom-designed microfluidic sensor offers rapid, highly sensitive, and specific diagnostic assay approaches for pathogen detection.

Applications of Graphene Quantum Dots in Biomedical Sensors

“…These sensors integrate a biological element with a physiochemical transducer to generate an electronic signal, which is directly proportional to the analyte concentration and subsequently conveyed to a detector [12]. Generally, the classification of biosensors depends on: (a) the type of receptors employed during the bio-recognition events, such as antibody [13], peptide [14], enzyme [15,16] aptamer [17], DNA [18] and molecularly imprinted polymer (MIP)-based sensors [19,20]; (b) the type of transducers involved, such as electrochemical [21], optical [22], piezoelectric [23] and calorimetric biosensors [24]. They can accomplish the requirements of rapid and specific sensing of the biomolecules as well as the real-time analysis of modern detection techniques.…”

“…They exhibit peroxidase (POD)-like catalytic features that result in a redox reaction between H 2 O 2 and an electron-donating substrate. In the sector of biosensors, an enzyme called horseradish peroxidase (HRP) is often associated with the labeling of secondary bioreceptors for the corresponding analyte determination, which in turn makes the assays more tedious and costlier [18]. To carry out these procedures faster and cost-effectively, GQDs are now utilized for replacing HRP-conjugated secondary bioreceptors [53,67,68].…”

Application of Zero-Dimensional Nanomaterials in Biosensing

“…AuNPs are also frequently used in pathogen detection (Altintas et al, 2018;Savas et al, 2018;. Outbreaks of zika virus (ZIKV) in the tropics have posed major challenges to global health in recent years.…”

Graphene Quantum Dot-Based Electrochemical Immunosensors for Biomedical Applications

“…The International Union of Pure and Applied Chemistry (IUPAC) defines a biosensor as "a device that uses specific biochemical reactions mediated by isolated enzymes, immunosystems, tissues, organelles or whole cells to detect chemical compounds usually by electrical, thermal or optical signals" [9]. These analytical devices convert a biological or chemical response into an electrical signal and are usually classified on the basis of the type of bioreceptors involved in bio-recognition events, i.e., enzyme [10], antibody [11], peptide [12], aptamer [13], DNA [14], and molecularly imprinted polymer (MIP)-based sensors [15,16], or according to the type of transducer employed, such as electrochemical [17], optical [18], piezoelectric [19], and calorimetric biosensors [20]. The general working principle behind all of the biosensors is portrayed in Figure 1.…”

“…They acquire peroxidase (POD)-mimicking catalytic properties, which lead to simultaneous oxidation and reduction of an electron-donor substrate and H 2 O 2 , respectively. In the field of biosensors, horseradish peroxidase (HRP), a peroxidase enzyme, is usually employed, where the labeling of a secondary receptor for target detection is a necessity, thus resulting in tedious and more expensive assay procedures [14]. To conduct these assays quickly and economically, GQDs can be employed to avoid HRP-labeled secondary antibodies [47,63,64].…”