Search

For early detection and diagnosis of cancer, it is essential to develop an electrochemical biosensor that is quick, accurate, and sensitive.

The prevalence of the inclusion or substitution of porcine and its derivatives in foods by imprudent food manufacturers accentuated the need for a sensitive and specific method to detect porcine DNA. This work aimed to develop and validate an EvaGreen dye-based quantitative real-time (qPCR) assay for porcine DNA analysis. The primer set used in this work targets a 95-bp fragment of the porcine cytochrome b gene. Application of the assay to dilutions of porcine genomic DNA showed that the assay is sensitive down to 10 pg/μL of porcine DNA and the detection limit, under binary admixture conditions, was 0.001%. A correlation coefficient (R2) of 0.998 and PCR efficiency of 101.6% over the dynamic range from 10 to 10000 pg/μL indicated that the assay has high linearity and efficiency. The method’s specificity towards porcine was revealed by the amplification profile, which only displayed an amplification signal for porcine DNA. These findings suggest that the developed assay is sensitive, specific, and rapid. In conclusion, the assay can be used as an alternative method to detect and quantify porcine DNA in raw and processed food products.

Abstract: Culturing meat in-vitro cell, also known as cellular agriculture, is an alternative to livestock meat production. By culturing meat instead of relying on conventional meat, the deleterious effects on the environment can be avoided. Moreover, depending on cultured meat resources will help improve animal welfare and aid in tackling the current sustainability challenges associated with animal rearing to produce meat. Multiple tissue culture methods and bioengineering techniques are currently being studied to design various cell types to develop muscle and fat cells for culturing meat. To succeed in the cellular agricultural industry, the public impression of cultured meat must also be considered. To better study and understand cultured meat perception among the public, we extensively studied papers on ‘cultured meat’ and ‘public perception’ from the past decade. Most recent research studies have discussed the public perception of a particular group toward cultured meat. However, to the best of our knowledge, no existing article provides a detailed study on recent advances in cultured meat and the views of public consumers from different backgrounds. Thus, this paper focuses on several religious and regional groups and their perceptions of cultured meat consumption. The consumers’ appeal and acceptability of cultured meat are crucial to manufacturing cultured meat. However, many existing studies on public perception of cultured meat have raised concerns despite their willingness to consume it. Therefore, organisations must carefully navigate for such an industry to reach its full potential. For instance, labels like ‘lab-grown meat’, ‘cultured meat’, or ‘artificial meat’ may elicit negative customer responses. On the contrary, tags like ‘clean meat’ or ‘healthy meat’ may promote better acceptance among consumers. Further research and development, especially on the alternative of serum-free culture media, cultured meat, and cellular agriculture, can transform the meat industry soon.

A label-free electrochemiluminescence biosensor using carbon nano-horns and nafion nanocomposite-modified carbon nanofiber printed sensor for the detection of porcine gelatin.

The rapid development of accurate and quick diagnostic tools for infectious diseases has made a massive impact in global health. POC devices for pathogen detection have primarily contributed to clinical management in various applications such as pathology, drug discovery and food safety. Diagnostic tests in isolated or remote areas were previously time-consuming, costly, and the methods were extensive and laborious. However, the new generation of miniaturized biosensor technologies aimed at POC testing resulted in a more sensitive, reliable, rapid and cost-effective detection process without needing sophisticated instruments. Among them, a few were developed as ready-to-use devices and are currently commercially available. In this review, we presented the most recent developments in diagnostic methods in pathogen detection and the improvements included in the detection steps in recent POCs for pathogen detection. We also discussed incorporating nanomaterials, microfluidics, lateral flow tests, screen-printed electrodes and smartphones into POC devices used in this area. The challenges and prospects of developing sample-to-results POC devices for pathogen detection were also discussed.

In recent years, rapid detection methods such as polymerase chain reaction (PCR) and quantitative real-time PCR (qPCR) have been continuously developed to improve the detection of food-borne pathogens in food samples. The recent developments of PCR and qPCR in the detection and identification of these food-borne pathogens are described and elaborated throughout this review. Specifically, further developments and improvements of qPCR are discussed in detecting Salmonella and norovirus. Promising advances in these molecular detection methods have been widely used to prevent human food-borne illnesses and death caused by the food-borne pathogens. In addition, this review presents the limitations and challenges of the detection methods which include conventional culture method and conventional PCR method in detecting Salmonella and norovirus. Furthermore, several advances of qPCR such as viability PCR (vPCR) and digital PCR (dPCR) have been discussed in the detection of Salmonella and norovirus. Good practice of analysis of the food-borne pathogens and other contaminants in the food industry as well as the advancement of molecular detection methods will help improve and ensure food safety and food quality.

Elevated levels of haptoglobin, a blood serum protein, have been implicated in a variety of disorders, such as cancer, diabetes mellitus, Crohn’s disease and Parkinson’s disease, to name a few. Due to its link to many disorders, it is therefore essential to develop a simple but sensitive technique for the detection of haptoglobin for the purpose of disease monitoring. To this end, we have developed a label-free electrochemical immunosensor that is superior to the conventional methods currently available for haptoglobin detection. The immunosensor involves simple physisorption of graphene nanoplatelets with the polysaccharide chitosan to develop a GNPs/Chi nanocomposite for subsequent detection of electrochemical signal, and together their collective properties synergistically resulted in a highly sensitive detection method. The immunosensor was able to detect a wide linear range of concentrations from 1 ng mL−1 to 30 fg mL−1 with a low limit of detection of 30 fg mL−1. This developed immunosensor has proven to be extremely selective with great reproducibility and stability, with resistance to interference for the detection of haptoglobin. It is additionally sensitive enough to detect haptoglobin in human serum samples.

Background: Immunoglobulin A (IgA) accounts for 15% of total protein production per day and plays a crucial role in the first-line immune defence. Recently, IgA has been established as a vital clinical biomarker for nephropathy, allergic asthma, celiac disease (CD), pneumonia, and asthma as well as some neurological disorders. In this work, we have studied several carbon nanomaterials (CNMs) having different dimensions (D): carbon nano-onions (CNOs) - 0D, single-walled carbon nanotubes (SWCNTs) - 1D, and graphene nanoplatelets (GNPs) - 2D, on glassy carbon electrode (GCE) to identify which CNMs (CNOs/SWCNTs/GNPs) work best to fabricate IgA based electrochemical immunosensor. Methods: Different CNMs (CNOs, SWCNTs, GNPs) were tested for high electric current on GCE using square wave voltammetry (SWV), and among them, GNPs modified GCE platform (GNPs/GCE) showcased the highest electric current. Therefore, GNPs/GCE was utilized for the development of highly sensitive label-free electrochemical immunosensor for the detection of Immunoglobulin A using SWV. Results: Despite the simple fabrication strategies employed, the fabricated sensor demonstrated a low limit of detection of 50 fg mL-1 with an extensive linear range of detection from 50 fg mL-1 to 0.1 μg mL-1. Conclusion: Fabricated immunosensor represented high stability, repeatability, specificity and resistance to most common interferences as well as great potential to analyse the real sample.

Biosensor technology is experiencing an unprecedented momentum that is driven by rapid advances in material science for utilization in various fields, and is constantly evolving to develop fast, simple and sensitive sensors. Here, we present a comprehensive and concise review on electrochemiluminescent (ECL) nanomaterial-based aptasensors including challenges and applications. ECL aptasensor combines the merits of a biosensor, selectivity of an aptamer, and sensitivity of ECL to construct sensitive and selective sensors. Signal amplification processes through the incorporation of nanomaterials are essential to further enhance the sensitivity of ECL sensing systems. Nanomaterials are commonly utilized in sensor fabrication as (i) electrode modifiers, (ii) nanocarriers, (iii) nanocatalysts, and (iv) luminophores. The review highlights the effects of integrating nanomaterials such as gold nanoparticles, metal nanoparticles, metal oxides, carbon nanomaterials, metal organic frameworks, and quantum dots using various research strategies that address signal amplification to enhance the ECL signal. Furthermore, various concepts have been demonstrated with relevant figures and explanations to serve as a general overview for the design of ECL aptasensors. Lastly, we discuss the underlying problems and possibilities for ECL aptasensor research and development.

An electrochemiluminescence (ECL) aptasensor for the detection of the milk protein allergen β-lactoglobulin (β-LG) using nanocomposite as luminophore was fabricated. The Ru-AuNPs/GNP/Naf complex was formed by combining the Rubpy

In recent years, rapid detection methods such as polymerase chain reaction (PCR) and quantitative real-time PCR (qPCR) have been continuously developed to improve the detection of food-borne pathogens in food samples. The recent developments of PCR and qPCR in the detection and identification of these food-borne pathogens are described and elaborated throughout this review. Specifically, further developments and improvements of qPCR are discussed in detecting

We propose a robust object-detector ensemble by introducing a dynamic multi-layer multi-label (MLML)-tree–based adaptive deep learning framework. In many heterogeneous data distributions, deep attributes show latent hierarchical clustering properties. Object detector performance can be enhanced using the dynamic MLML-tree, which can adjust the ambiguities between inter-class nodes and variations between sub-class nodes. In the MLML-tree, dynamic multi-label (DML) trees are configured in two layers and adapt to using a sparse working dataset. First, coarse object clusters are built using an outlier-aware soft-clustering algorithm. Each coarse cluster is denoted by an inter-class node and is associated with an adaptive object detector in DML tree layer 1. It is built by recursively partitioning inter-class nodes until homogeneous object-class leaves are built. DML tree layer 2 is built for each object-class node, which is associated with a convolutional neural network detector, recursively. A novel sub-class can be learned automatically in DML tree layer 2 by applying semi-supervised learning. Extensive experiments show that the proposed method is superior to state-of-the-art techniques using PASCAL Visual Object Classes (VOC) 2007, VOC 2012, and the Microsoft Common Objects in Context (COCO) datasets.

An electrochemical label-free aptasensor platform was developed by using amine-functionalized aptamer that was incorporated onto screen-printed carbon electrode (SPCE) modified with graphene nanoplatelets (GNPs) for the detection of lipocalin-2 (LCN-2) protein. The aptamers were covalently bound to the GNPs surface via 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and $N$ -hydroxysuccinimide (NHS) chemistry and were used as the molecular recognition element for the target protein. Successful interaction between aptamer and LCN-2 protein was ascertained via electrochemical probe, ferro-, and ferri-cyanide {Fe(CN)63−/4−} and monitored by means of square wave voltammetry (SWV) whilst layer-by-layer fabrication study was done using cyclic voltammetry (CV). The developed LCN-2 aptasensor achieved sub-picomolar detection of the protein, with the detection limit determined as 0.07 pg ml−1, and a dynamic linear range of 0.1 to 10 pg ml−1. Fabricated aptasensor successfully demonstrated high selectivity, stability, and reproducibility as well as displaying potential for the in vitro detection of LCN-2 in real serum samples.

Generation of ECL by a set of luminophore-corectant system is highly dependent on the concentration of the luminophore, coreactant; applied photomultiplier tube (PMT) voltage; materials, dimensions and the surface area of the electrode. Therefore, in this work firstly concentration of the luminophore ([Ru(bpy)3]2+), coreactant (TPrA); applied voltage on PMT was optimised for the high ECL intensity with the carbon nanofiber screen-printed electrode (CNFs-SPE). Secondly, with the optimised concentration of the [Ru(bpy)3]2+, TPrA and optimised applied PMT voltage; ECL intensity of the bare poly(3,4-ethylenedioxythiophene) screen-printed electrode (PEDOT-SPE), carbon screen-printed electrode (C-SPE) and CNFs-SPE was compared. Study demonstrated that the ECL generated on the surface of the PEDOT-SPE, C-SPE and CNFs-SPE was 1214 (a.u.), 3779 (a.u.), and 6346 (a.u.) respectively. Thirdly, bare CNFs-SPE was modified with Chitosan, and nanocomposite of: SWCNTs/Chitosan, CdTe-QDs/Chitosan, AuNPs/Chitosan, CdTe-QDs/SWCNTs/Chitosan, AuNPs/SWCNTs/Chitosan, CdTe-QDs/AuNPs/Chitosan, and AuNPs/CdTe-QDs/SWCNTs/Chitosan; and their ECL was compared. This study illustrated that AuNPs/CdTe-QDs/SWCNTs/Chitosan-nanocomposite modified CNFs-SPE (AuNPs/CdTe-QDs/SWCNTs/Chitosan/CNFs-SPE) displayed highest ECL (10,452 a.u.), and ~ 200% more as compare to the bare CNFs-SPE. Further, AuNPs/CdTe-QDs/SWCNTs/Chitosan/CNFs-SPE displayed ~ 200% increase in effective surface area and electronic conductivity in comparison to the bare CNFs-SPE. In the fourth and last study, ECL stability of the AuNPs/CdTe-QDs/SWCNTs/Chitosan-nanocomposite for continuous 10 cycles was studied, which showed that AuNPs/CdTe-QDs/SWCNTs/Chitosan/CNFs-SPE was highly stable with only ~ 10% decrease in ECL intensity.

In this study, a direct and label-free immunosensor was designed and constructed by modifying the screen-printed electrode with graphene nanoplatelets (GNPs) for the detection of the cardiac troponin T (cTnT). Firstly, GNPs were drop-casted onto carbon working electrode. Monoclonal cTnT antibodies were then immobilized on the GNPs via physical adsorption; finally, BSA was introduced to block non-specific binding sites. The detection of cTnT was performed using an electrochemiluminescence (ECL) technique with tris(bipyridine)ruthenium(II) chloride ([Ru(bpy)3]Cl2) used as a luminophore and TPrA (tripropylamine) as a co-reactant. The ECL intensity was demonstrated to be directly proportional to the cTnT concentration where a linear range from 100 pg mL-1 to 5 fg mL-1 of the cTnT detection was established. An extremely low limit of detection was achieved to be 0.05 fg mL-1 with an outstanding specificity. Additionally, this immunosensor showed excellent percentage recovery for real samples analyses in artificially spiked human serum.

This work reports on the first electrochemiluminescence (ECL) immunosensor employing a novel nanostructured composite of titanium dioxide (TiO