The primary goal of glucose sensing at the point of care is to identify glucose concentrations within the diabetes range. However, lower glucose levels also pose a severe health risk. In this paper, we propose quick, simple, and reliable glucose sensors based on the absorption and photoluminescence spectra of chitosan-capped ZnS-doped Mn nanomaterials in the range of 0.125 to 0.636 mM glucose corresponding to 2.3 mg/dL to 11.4 mg/dL. The detection limit was 0.125 mM (or 2.3 mg/dL), much lower than the hypoglycemia level of 70 mg/dL (or 3.9 mM). Chitosan-capped ZnS-doped Mn nanomaterials retain their optical properties while improving sensor stability. This study reports for the first time how the sensors’ efficacy was affected by chitosan content from 0.75 to 1.5 wt.%. The results showed that 1 %wt chitosan-capped ZnS-doped Mn is the most-sensitive, -selective, and -stable material. We also put the biosensor through its paces with glucose in phosphate-buffered saline. In the same range of 0.125 to 0.636 mM, the sensors-based chitosan-coated ZnS-doped Mn had a better sensitivity than the working water environment.

Biosensors have emerged as a pivotal technology in the biomedical field, significantly enhancing the rapidity and precision of biomolecule detection. These advancements are instrumental in refining diagnostic processes, optimizing treatments, and monitoring diseases more effectively. Central to the development of highly sensitive, selective, and stable biosensors are the bioreceptor and transducer components. This review paper discusses the use of lectin as a bioreceptor and explores the prevalent transducer methods employed in lectin-based biosensors, with a particular emphasis on their applications in biomedical research. The paper meticulously examines various transducers, with a spotlight on electrochemical and optical transduction methods, drawing from a wealth of previous studies to offer a comprehensive perspective on the application of these sensors in critical biomedical areas. These areas include early diagnosis, therapeutic interventions, and continuous health monitoring. Moreover, the review addresses the challenges of implementing lectin-based biosensors, such as specificity and stability issues. It also explores future possibilities, examining potential trends to overcome these challenges. In summary, this comprehensive analysis aspires to equip researchers with profound insights into the transformative potential of lectin-based biosensors, underscoring their significant role in the evolution of biomedical research and the broader healthcare landscape.

A typical glucose sensor is a glucose oxidase enzyme-based sensor due to its high sensitivity and selectivity. However, it has difficulty activating and stabilizing the enzyme. To enhance the stability of glucose oxidase-based sensors, chitosan is added to ZnS-doped Mn nanoparticles. Chitosan stabilizes the ZnS-doped Mn particles and can induce charge processes such as creation, transfer, and separation at the polymer interface and nanoparticles' interface. Hence, it is a strong candidate for electrochemical glucose sensing applications. This paper reports the impedance biosensor based on ZnS-doped Mn-capped chitosan nanomaterials and micro-interdigitated electrodes. The glucose sensors' high sensitivity, accuracy, and stability are obtained in the range of 2 mM to 10 mM. In addition, an application of the Canny edge detection to enhance the limit of detection is demonstrated using experimental data.

The global threat of antibiotic resistance has increased the importance of the detection of antibiotics. Conventional methods to detect antibiotics are time-consuming and require expensive specialized equipment. Here, we present a simple and rapid biosensor for detecting ampicillin, a commonly used antibiotic. Our method is based on the fluorescent properties of chitosan-coated Mn-doped ZnS micromaterials combined with the β-lactamase enzyme. The biosensors exhibited the highest sensitivity in a linear working range of 13.1–72.2 pM with a limit of detection of 8.24 pM in deionized water. In addition, due to the biological specificity of β-lactamase, the proposed sensors have demonstrated high selectivity over penicillin, tetracycline, and glucose through the enhancing and quenching effects at wavelengths of 510 nm and 614 nm, respectively. These proposed sensors also showed promising results when tested in various matrices, including tap water, bottled water, and milk. Our work reports for the first time the cost-effective (Mn:ZnS)Chitosan micromaterial was used for ampicillin detection. The results will facilitate the monitoring of antibiotics in clinical and environmental contexts.

Tetracycline hydrochloride is a widely used antibiotic for treating bacterial infections, but its misuse poses serious health risks. Therefore, it is crucial to accurately detect tetracycline in complex matrices. In this study, we propose a simple, enzyme-free absorbance biosensor for tetracycline detection based on the optical properties of chitosan-capped ZnS doped with Mn nanomaterials. The biosensor can detect tetracycline in a range from 13.1 pM to 72.2 pM, with the best detection limit being 2.13 pM in deionized water. It can also differentiate tetracycline from ampicillin, penicillin, cephalexin, amoxicillin, and glucose within the aforementioned range. Moreover, this novel sensor has proven reliable over time, and its performance has been demonstrated in tap water and milk. The results have the potential to revolutionize antibiotic monitoring in clinical and environmental settings, thus contributing to the global fight against antibiotic resistance.