Testosterone Imprinted poly(HEMA‐MAA) Nanoparticles Based Surface Plasmon Resonance Sensor for Detection of Testosterone

Molecularly Imprinted Polymer-Based Sensors for the Detection of Skeletal- and Cardiac-Muscle-Related Analytes

Molecularly imprinted polymers (MIPs) are synthetic polymers with specific binding sites that present high affinity and spatial and chemical complementarities to a targeted analyte. They mimic the molecular recognition seen naturally in the antibody/antigen complementarity. Because of their specificity, MIPs can be included in sensors as a recognition element coupled to a transducer part that converts the interaction of MIP/analyte into a quantifiable signal. Such sensors have important applications in the biomedical field in diagnosis and drug discovery, and are a necessary complement of tissue engineering for analyzing the functionalities of the engineered tissues. Therefore, in this review, we provide an overview of MIP sensors that have been used for the detection of skeletal- and cardiac-muscle-related analytes. We organized this review by targeted analytes in alphabetical order. Thus, after an introduction to the fabrication of MIPs, we highlight different types of MIP sensors with an emphasis on recent works and show their great diversity, their fabrication, their linear range for a given analyte, their limit of detection (LOD), specificity, and reproducibility. We conclude the review with future developments and perspectives.

Development of Optical-Based Molecularly Imprinted Nanosensors for Adenosine Detection

Adenosine nucleoside is an important molecule in human physiology. The levels of adenosine nucleoside in urine and plasma are directly or indirectly related to diseases such as neurodegenerative diseases and cancer. In the present study, adenosine-imprinted and non-imprinted poly(2-hydroxyethyl methacrylate-methacrylic acid) (poly(HEMA-MAA)) surface plasmon resonance (SPR) nanosensors were prepared for the determination of adenosine nucleoside. First, MAA/adenosine pre-polymerization complexes were prepared at different molar ratios using adenosine as a template molecule and methacrylic acid (MAA) as a monomer, and SPR nanosensor surfaces were optimized by determining the highest imprinting factor of the chip surfaces. The surfaces of adenosine-imprinted and non-imprinted SPR nanosensors were characterized by using atomic force microscopy, ellipsometry, and contact angle measurements. Kinetic analyses were made with different concentrations in the range of 0.5-400.0 nM for the detection range with a pH 7.4 phosphate buffer solution. The limit of detection in adenosine aqueous solutions, artificial plasma, and artificial urine was determined to be 0.018, 0.015, and 0.013 nM, respectively. In the selectivity analysis of the developed nanosensors, the selectivity of adenosine SPR nanosensors in solutions at different concentrations was determined by using guanosine and cytidine nucleosides. The relative selectivity coefficients of adenosine-imprinted SPR nanosensors for adenosine/cytidine and adenosine/guanosine are 3.836 and 3.427, respectively. Since adenosine-imprinted SPR nanosensors are intended to be used in medical analysis and research, adenosine analysis has also been studied in artificial urine and artificial plasma samples.

A label-free fluorescent aptamer sensor for testosterone based on SYBR Green I

Testosterone is a steroid hormone that plays an indispensable role in the normal metabolism of organisms. However, exogenous testosterone, even as low as nmol L^-1, will harm the human body due to accumulation. In this study, we developed an unlabeled fluorescent sensor for testosterone based on SYBR Green I. SYBR Green I is a fluorescent dye that can be embedded into the G-quadruplex of the testosterone aptamer T5. The fluorescence quenching effect is utilized to achieve quantitative detection, which occurs by the competition between testosterone and SYBR Green I for the T5 aptamer binding sites. In this work, we optimized the detection conditions to make the fluorescent sensor more sensitive and verify the specificity, linear range, and detection ability in the buffer and real water samples. The sensor's LOD and LOQ values were 0.27 nmol L^-1 and 0.91 nmol L^-1, respectively, while the detection range was linear from 0.91 nmol L^-1 to 2000 nmol L^-1. According to the results, the sensor shows high specificity and good performance even in real sample detection such as tap water and river water, providing an alternative method for the quantitative detection of testosterone in the environment, which is more convenient and efficient.

TESTOSTERONE BIOSENSOR IN SPORTS DOPING

ABSTRACT Introduction: Testosterone is a steroid that can help with blood disorders, sexual dysfunctions, connective tissue diseases, some malignancies, intractable pain, and other serious diseases. However, it must be prescribed under medical supervision because of the risk of major adverse effects such as liver disease, heart disease, stroke, blood clots, and cancer. There is an urgent need for research on developing an electrochemical sensor to detect testosterone as a doping substance in sports. Objective: Develop an electrochemical sensor of poly(ionic liquid)-graphene oxide molecularly printed polymers (PIL/MIs/GO) to detect testosterone as a doping substance in sports. Methods: Morphological characterization of modified electrodes was performed by field emission scanning electron microscopy (FESEM), allowing the GO to be surface-mounted with fragments and apertures. Due to the holes generated by the agglomeration of PIL and MIs molecules on the wavy edges of the GO nanosheets, the surface morphology of PIL/MIs/GO/GCE also revealed a high porosity structure. Results: Compared to other synergistic influences of GO nanosheets with PIL and MIs molecules, electrochemical investigations using a differential pulse voltammetry approach indicated high selectivity, good stability, appropriate linear range, lower detection limit, and higher selectivity. Conclusion: In pharmaceutical samples and human biological fluids, the validity and accuracy of PIL/MIs/GO/GCE for the determination of testosterone demonstrated practical application. PIL/MIs/GO/GCE can thus be used as an accurate and reliable sensor for detecting testosterone as a doping agent in sports. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.