The electrochemical immunosensor for detection of prostatic specific antigen using quince seed mucilage-GNPs-SNPs as a green composite

Stimuli-responsive glucuronoxylan polysaccharide from quince seeds for biomedical, food packaging, and environmental applications

Mucilage is a gelatinous mixture of polysaccharides secreted from the seed coat and/or pericarp of many plant seeds when soaked in water. Mucilage affected seed germination while maintaining hydration levels during scarcity. Cydonia oblonga (quince) seeds are natural hydrocolloids extruding biocompatible mucilage mainly composed of polysaccharides. Quince seed mucilage (QSM) has fascinated researchers due to its applications in the food and pharmaceutical industries. On a commercial scale, QSM preserved the sensory and physiochemical properties of various products such as yogurt, desserts, cakes, and burgers. QSM is responsive to salts, pH, and solvents and is mainly investigated as edible coatings in the food industry. In tablet formulations, modified and unmodified QSM as a binder sustained the release of various drugs such as cefixime, capecitabine, diclofenac sodium, theophylline, levosulpiride, diphenhydramine, metoprolol tartrate, and acyclovir sodium. QSM acted as a reducing and capping agent to prepare nanoparticles for good antimicrobial resistance, photocatalytic characteristics, and wound-healing potential. The present review discussed the extraction optimization, chemical composition, stimuli-responsiveness, and viscoelastic properties of mucilage. The potential of mucilage in edible films, tissue engineering, and water purification will also be discussed.

Multiplexed Opto-Microfluidic Biosensing: Advanced Platform for Prostate Cancer Detection

Cancer stands as a prominent global cause of mortality, necessitating early detection to augment survival rates and alleviate economic burdens on healthcare systems. In particular, prostate cancer (PCa), impacting 1.41 million men globally in 2020, accentuates the demand for sensitive and cost-effective detection methods beyond traditional prostate-specific antigen (PSA) testing. While clinical techniques exhibit limitations, biosensors emerge as compact, user-friendly alternatives to traditional laboratory approaches. However, existing biosensors predominantly concentrate on PSA detection, prompting the necessity for advancing toward multiplex sensing platforms. This study introduces a compact opto-microfluidic sensor featuring a substrate of gold nanospikes, fabricated via electrodeposition, for enhanced sensitivity. Embedded within a microfluidic chip, this nanomaterial enables the precise and concurrent measurement of PSA, alongside two complementary PCa biomarkers, matrix metalloproteinase-2 (MMP-2) and anti-α-methylacyl-CoA racemase (anti-AMACR) in diluted human plasma, offering a comprehensive approach to PSA analysis. Taking advantage of the localized surface plasmon resonance principle, this biosensor offers robustness and sensitivity in real sample analysis without the need for labeling agents. With the limit of detection at 0.22, 0.37, and 0.18 ng/mL for PSA, MMP-2, and anti-AMACR, respectively, this biosensing platform holds promise for point-of-care analysis, underscoring its potential impact on medical diagnostics.

2D graphene-based advanced nanoarchitectonics for electrochemical biosensors: Applications in cancer biomarker detection

Low-cost, rapid, and easy-to-use biosensors for various cancer biomarkers are of utmost importance in detecting cancer biomarkers for early-stage metastasis control and efficient diagnosis. The molecular complexity of cancer biomarkers is overwhelming, thus, the repeatability and reproducibility of measurements by biosensors are critical factors. Electrochemical biosensors are attractive alternatives in cancer diagnosis due to their low cost, simple operation, and promising analytical figures of merit. Recently graphene-derived nanostructures have been used extensively for the fabrication of electrochemical biosensors because of their unique physicochemical properties, including the high electrical conductivity, adsorption capacity, low cost and ease of mass production, presence of oxygen-containing functional groups that facilitate the bioreceptor immobilization, increased flexibility and mechanical strength, low cellular toxicity. Indeed, these properties make them advantageous compared to other alternatives. However, some drawbacks must be overcome to extend their use, such as poor and uncontrollable deposition on the substrate due to the low dispersity of some graphene materials and irreproducibility of the results because of the differences in various batches of the produced graphene materials. This review has documented the most recently developed strategies for electrochemical sensor fabrication. It differs in the categorization method compared to published works to draw greater attention to the wide opportunities of graphene nanomaterials for biological applications. Limitations and future scopes are discussed to advance the integration of novel technologies such as artificial intelligence, the internet of medical things, and triboelectric nanogenerators to eventually increase efficacy and efficiency.

Microfluidic Platform Integrated with Carbon Nanofibers-Decorated Gold Nanoporous Sensing Device for Serum PSA Quantification

Prostate cancer is a disease with a high incidence and mortality rate in men worldwide. Serum prostate-specific antigens (PSA) are the main circulating biomarker for this disease in clinical practices. In this work, we present a portable and reusable microfluidic device for PSA quantification. This device comprises a polymethyl methacrylate microfluidic platform coupled with electrochemical detection. The platinum working microelectrode was positioned in the outflow region of the microchannel and was modified with carbon nanofibers (CNF)-decorated gold nanoporous (GNP) structures by the dynamic hydrogen bubble template method, through the simultaneous electrodeposition of metal precursors in the presence of CNF. CNF/GNP structures exhibit attractive properties, such as a large surface to volume ratio, which increases the antibody's immobilization capacity and the electroactive area. CNFs/GNP structures were characterized by scanning electron microscopy, energy dispersive spectrometry, and cyclic voltammetry. Anti-PSA antibodies and HRP were employed for the immune-electrochemical reaction. The detection limit for the device was 5 pg mL^-1, with a linear range from 0.01 to 50 ng mL^-1. The coefficients of variation within and between assays were lower than 4.40%, and 6.15%, respectively. Additionally, its clinical performance was tested in serum from 30 prostate cancer patients. This novel device was a sensitive, selective, portable, and reusable tool for the serological diagnosis and monitoring of prostate cancer.

Anticancer Phytochemical-Based Nanoformulations: Therapeutic Intervention in Cancer Cell Lines

Phytochemicals have the potential to treat resistant cancer. They are delivered to the target site via nano-based carriers. Promising results are seen in preclinical and in vitro models, as phytochemical-based nanoformulations have improved cell cytotoxicity compared to single agents. They can synergistically inhibit cancer cell growth through p53 apoptosis in MCF-7 breast cancer cell lines. Moreover, synergic viability in reproducible glioma models at half inhibitory concentrations has been shown. Through caspase activation, phytochemical-based nanoformulations also increase cell death in 4T1 breast cancer cell lines. They have shown improved cytotoxicity at half inhibitory concentrations compared to single-agent drugs in cervical cancer. In terms of colorectal cancer, they have the potential to arrest cells in the S phase of the cell cycle and synergistically inhibit cell proliferation. In squamous cell carcinoma of the tongue, they inhibit protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathways. This review reports on developments in the therapeutic management of various cancers using phytochemical-based nanoformulations, which have shown potential benefits in the clinical management of cancer patients, halting/slowing the progression of the disease and ameliorating chemotherapy-induced toxicities.

A Comprehensive Review on Biopolymer Mediated Nanomaterial Composites and Their Applications in Electrochemical Sensors

Biopolymers are an attractive green alternative to conventional polymers, owing to their excellent biocompatibility and biodegradability. However, their amorphous and nonconductive nature limits their potential as active biosensor material/substrate. To enhance their bio-analytical performance, biopolymers are combined with conductive materials to improve their physical and chemical characteristics. We review the main advances in the field of electrochemical biosensors, specifically the structure, approach, and application of biopolymers, as well as their conjugation with conductive nanoparticles, polymers and metal oxides in green-based noninvasive analytical biosensors. In addition, we reviewed signal measurement, substrate bio-functionality, biochemical reaction, sensitivity, and limit of detection (LOD) of different biopolymers on various transducers. To date, pectin biopolymer, when conjugated with either gold nanoparticles, polypyrrole, reduced graphene oxide, or multiwall carbon nanotubes forming nanocomposites on glass carbon electrode transducer, tends to give the best LOD, highest sensitivity and can detect multiple analytes/targets. This review will spur new possibilities for the use of biosensors for medical diagnostic tests.

A Novel, Quick, and Reliable Smartphone-Based Method for Serum PSA Quantification: Original Design of a Portable Microfluidic Immunosensor-Based System

Simple Summary

Prostate cancer (PCa) is the most frequently diagnosed malignancy and second most common cause of cancer-related death in males. An early diagnosis is crucial to improve the prognosis. Prostate-Specific Antigen (PSA) is the most widely used biomarker for PCa, but this type of biomarker analysis is performed in centralized laboratories, delaying the diagnosis and initiation of treatment. Our team has developed a miniaturized platform for portable PSA quantification to overcome this shortcoming. It includes a microfluidic chip, immune capture of PSA by magnetic microbeads, and electrochemical quantification. The utilization of a micro-potentiostat allows PSA levels to be read on a smartphone in less than 30 min. This technique was found to offer a fast, easy, specific, sensitive, and reproducible method for PSA quantification. Further research is warranted to verify these findings and explore its potential application at all health care levels.

Abstract

We describe a versatile, portable, and simple platform that includes a microfluidic electrochemical immunosensor for prostate-specific antigen (PSA) detection. It is based on the covalent immobilization of the anti-PSA monoclonal antibody on magnetic microbeads retained in the central channel of a microfluidic device. Image flow cytometry and scanning electron microscopy were used to characterize the magnetic microbeads. A direct sandwich immunoassay (with horseradish peroxidase-conjugated PSA antibody) served to quantify the cancer biomarker in serum samples. The enzymatic product was detected at −100 mV by amperometry on sputtered thin-film electrodes. Electrochemical reaction produced a current proportional to the PSA level, with a linear range from 10 pg mL⁻¹ to 1500 pg mL⁻¹. The sensitivity was demonstrated by a detection limit of 2 pg mL⁻¹ and the reproducibility by a coefficient of variation of 6.16%. The clinical performance of this platform was tested in serum samples from patients with prostate cancer (PCa), observing high specificity and full correlation with gold standard determinations. In conclusion, this analytical platform is a promising tool for measuring PSA levels in patients with PCa, offering a high sensitivity and reduced variability. The small platform size and low cost of this quantitative methodology support its suitability for the fast and sensitive analysis of PSA and other circulating biomarkers in patients. Further research is warranted to verify these findings and explore its potential application at all healthcare levels.

Metallic and Metal Oxides Nanoparticles for Sensing Food Pathogens—An Overview of Recent Findings and Future Prospects

Nowadays, special importance is given to quality control and food safety. Food quality currently creates significant problems for the industry and implicitly for consumers and society. The effects materialize in economic losses, alterations of the quality and organoleptic properties of the commercial products, and, last but not least, they constitute risk factors for the consumer’s health. In this context, the development of analytical systems for the rapid determination of the sanitary quality of food products by detecting possible pathogenic microorganisms (such as Escherichia coli or Salmonella due to the important digestive disorders that they can cause in many consumers) is of major importance. Using efficient and environmentally friendly detection systems for identification of various pathogens that modify food matrices and turn them into food waste faster will also improve agri-food quality throughout the food chain. This paper reviews the use of metal nanoparticles used to obtain bio nanosensors for the purpose mentioned above. Metallic nanoparticles (Au, Ag, etc.) and their oxides can be synthesized by several methods, such as chemical, physical, physico-chemical, and biological, each bringing advantages and disadvantages in their use for developing nanosensors. In the “green chemistry” approach, a particular importance is given to the metal nanoparticles obtained by phytosynthesis. This method can lead to the development of good quality nanoparticles, at the same time being able to use secondary metabolites from vegetal wastes, as such providing a circular economy character. Considering these aspects, the use of phytosynthesized nanoparticles in other biosensing applications is also presented as a glimpse of their potential, which should be further explored.

Construction of a sensitive and selective plasmonic biosensor for prostate specific antigen by combining magnetic molecularly-imprinted polymer and surface-enhanced Raman spectroscopy

Selective and sensitive detection of cancer biomarkers in serum samples is critical for early diagnosis of cancer. Prostate specific antigen is an important biomarker of prostate cancer, which ranks high among cancer-related deaths of men over 50 years old. Herein, a novel analytical method was introduced for detection of PSA by combining high selectivity of molecularly-imprinted polymers and high sensitivity of surface-enhanced Raman spectroscopy (SERS). Firstly, magnetic nanoparticles were grafted with an imprinted layer by using tannic acid as a functional monomer, diethylenetriamine as a cross-linker and prostate specific antigen as a template molecule. Detailed surface characterization and re-binding experiment results indicated that the imprinting of the antigen was successful with an imprinting factor of 5.58. The prepared magnetic molecularly imprinted polymers (MMIPs) were used as an antibody-free capture probe and labeled with gold nanoparticles that were modified with anti-PSA and a Raman reporter, namely 5,5'-dithiobis-(2-nitrobenzoic acid). Thus, a plasmonic structure (sandwich complex) was formed between MMIP and the SERS label. The limit of detection and limit of quantification of the designed sensor were 0.9 pg/mL and 3.2 pg/mL, respectively. The sensor also showed high recovery rates (98.0-100.1% for healthy person and 99.0-101.3% for patient) with low standard deviations (less than 4.3% for healthy person and less than 3.3% for patient) for PSA in serum samples. Compared with the traditional immunoassays, the proposed method has several advantages like low cost, reduced detection procedure, fast response, high sensitivity and selectivity. It is believed that the proposed method can be potentially used for selective and sensitive determination of tumor marker of prostate cancer in clinical applications.

Biosensing strategies for diagnosis of prostate specific antigen

Almost from the time of its discovery, the prostate specific antigen (PSA) has been one of the most accurate and most extensively studied indicators of prostate cancer (PC). Because of advancements in biosensing systems and technology, PSA analysis methods have been substantially updated and enhanced as compared to their first instances. With the development of techniques in biosensor technology, the number of PSA biosensors that can be used in the biomedical sector is increasing year by year. Many different recognition elements and transducers have been used in the development of biosensor systems that exhibit high sensitivity, selectivity, and specificity. Here in this review, we provide a current overview of the different approaches to PSA detection.