An electrochemical biosensing platform for progesterone hormone detection using magnetic graphene oxide

Rapid label-free impedimetric detection of progesterone enhanced by immunomagnetic bead-based competitive immunoreaction

Detecting progesterone (P4) concentration in cow serum is essential for monitoring the pregnancy progress after fertilization and is significant for the dairy farming industry and veterinary medicine. This study reports enzyme-free immunomagnetic beads (IMBs)-based competitive immunoassay for detecting P4 by P4-bovine serum albumin (BSA)-modified biosensors. The anti-P4 antibody-conjugated IMBs serve as collectors to capture P4 in undiluted serum samples to prevent the biosensor surface from biosample contamination and as insulated labels to report the electron-transfer resistance signal of electrochemical impedance spectroscopy (EIS) measurement. The IMBs and P4-containing samples were mixed for 15-30 min, capable of obtaining stable P4@IMB complexes. The 0.2-kGauss pulsed magnetic field (PMF) of the 20-s pulse width and 20-s relaxation time applied for 5 min can shorten the immunoreaction time between the P4@IMBs and the P4-BSA-modified biosensor and reduce the IMB's nonspecific adsorption on the biosensor surface. This competitive immunoassay's cut-off value and detection limit were 7.71 ng/mL and 7.33 ng/mL, respectively, which is lower than the serum's P4 plateau concentration (over 8 ng/mL) of dairy cows on days 6-16 of estrus cycles and that in pregnancy. The IMB-based immunoassay combining the PMF attraction and the label-free EIS measurement exhibits promising potential for rapidly detecting P4 in undiluted serum.

Advances in human reproductive biomarkers

Reproductive biomarkers are important regulators in women, especially during pregnancy and childbirth. Because of their essential role in women's health, the discovery and quantification of reproductive biomarkers is of great clinical importance. Nowadays, there are many detection strategies to detect these biomarkers, including VEGF, human chorionic gonadotropin (hCG), etc. Consider the limitations and problems of conventional diagnostic methods, new methods are being developed, one of the most important being methods based on nanotechnology. This review includes a review of methods for diagnosing reproductive biomarkers, ranging from mainstream to nanotechnology-based methods. The bulk of this article is an in-depth introduction to the latest advances in biosensor and nanosensor research for the detection and quantitative identification of reproductive biomarkers.

Tip-Enhanced Sub-Femtomolar Steroid Immunosensing via Micropyramidal Flexible Conducting Polymer Electrodes for At-Home Monitoring of Salivary Sex Hormones

Noninvasive testing and continuous monitoring of ultralow-concentration hormones in biofluids have attracted increasing interest for health management and personalized medicine, in which saliva could fulfill the demand. Steroid sex hormones such as progesterone (P4) and β-estradiol (E2) are crucial for female wellness and reproduction; however, their concentrations in saliva can vary down to sub-pM and constantly fluctuate over several orders of magnitude. This remains a major obstacle toward user-friendly and reliable monitoring at home with low-cost flexible biosensors. Herein we introduce a 3D micropyramidal electrode architecture to address such challenges and achieve an ultrasensitive flexible electrochemical immunosensor with sub-fM-level detection capability of salivary sex hormones within a few minutes. This is enabled by micropyramidal electrode arrays consisting of a poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) thin film as the coating layer and electrochemically decorated gold nanoparticles (AuNPs) to improve the antibody immobilization. The enhanced mass transport around the 3D tips provided by the micropyramidal architecture is discovered to improve the detection limit by 3 orders of magnitude, pushing it to as low as ∼100 aM for P4 and ∼20 aM for E2, along with a wide linear range up to μM. Accordingly, these hormones down to sub-fM in >1000-fold-diluted saliva samples can be accurately measured by the printed soft immunosensors, thus allowing at-home testing through simple saliva dilution to minimize the interfering substances instead of centrifugation. Finally, monitoring of the female ovarian hormone cycle of both P4 and E2 is successfully demonstrated based on the centrifuge-free saliva testing during a period of 4 weeks. This ultrasensitive and soft 3D microarchitected electrode design is believed to provide a universal platform for a diverse variety of applications spanning from accurate clinical diagnostics and counselling and in vivo detection of bioactive species to environmental and food quality tracing.

Progesterone and β-hCG Determination Using an Electrochemical Combo-Strip for Pregnancy Monitoring

The development of analytical devices that can allow an easy, rapid and cost-effective measurement of multiple markers, such as progesterone and β-hCG, could have a role in decreasing the burden associated with pregnancy-related complications, such as ectopic pregnancies. Indeed, ectopic pregnancies are a significant contributor to maternal morbidity and mortality in both high-income and low-income countries. In this work, an effective and highly performing electrochemical strip for a combo determination of progesterone and β-hCG was developed. Two immunosensing approaches were optimized for the determination of these two hormones on the same strip. The immunosensors were realized using cost-effective disposable electrode arrays and reagent-saving procedures. Each working electrode of the array was modified with both the IgG anti-β-hCG and anti-progesterone, respectively. By adding the specific reagents, progesterone or β-hCG can then be determined. Fast quantitative detection was achieved, with the analysis duration being around 1 h. Sensitivity and selectivity were assessed with a limit of detection of 1.5 × 10-2 ng/mL and 2.45 IU/L for progesterone and β-hCG, respectively. The proposed electrochemical combo-strip offers great promise for rapid, simple, cost-effective, and on-site analysis of these hormones and, thus, for the development of a point-of-care diagnostic tool for early detection of pregnancy-related complications.

Electrochemical biosensors for monitoring of selected pregnancy hormones during the first trimester: A systematic review

The hormones human chorionic gonadotropin, progesterone, estrogen and four of its metabolites (estradiol, estrone, estriol, estetrol), as well as relaxin play an essential role in the development of the fetus during the first trimester. Imbalances in these hormones during the first trimester have been directly linked to miscarriages. However, frequent monitoring of the hormones is limited by the current conventional centralized analytical tools that do not allow a rapid response time. Electrochemical sensing is considered an ideal tool to detect hormones owing to its advantages such as quick response, user-friendliness, low economic costs, and possibility of use in point-of-care settings. Electrochemical detection of pregnancy hormones is an emerging field that has been demonstrated primarily at research level. Thus, it is timely with a comprehensive overview of the characteristics of the reported detection techniques. This is the first extensive review focusing on the advances related to electrochemical detection of hormones linked to the first trimester of pregnancy. Additionally, this review offers insights into the main challenges that must be addressed imminently to ensure progress from research to clinical applications.

Carbon Dots Conjugated Antibody as an Effective FRET-Based Biosensor for Progesterone Hormone Screening

In this work, carbon dots (CDs) were synthesized by a one-step hydrothermal method using citric acid and ethylene diamine, and covalently functionalized with antibodies for the sensing of progesterone hormone. The structural and morphological analysis reveals that the synthesized CDs are of average size (diameter 8-10 nm) and the surface functionalities are confirmed by XPS, XRD and FT-IR. Further graphene oxide (GO) is used as a quencher due to the fluorescence resonance energy transfer (FRET) mechanism, whereas the presence of the analyte progesterone turns on the fluorescence because of displacement of GO from the surface of CDs effectively inhibiting FRET efficiency due to the increased distance between donor and acceptor moieties. The linear curve is obtained with different progesterone concentrations with 13.8 nM detection limits (R2 = 0.974). The proposed optical method demonstrated high selectivity performance in the presence of structurally resembling interfering compounds. The PL intensity increased linearly with the increased progesterone concentration range (10-900 nM) under the optimal experimental parameters. The developed level-free immunosensor has emerged as a potential platform for simplified progesterone analysis due to the high selectivity performance and good recovery in different samples of spiked water.

Advances in electrochemical sensors based on nanomaterials for the detection of lipid hormone

Lipid hormone is produced by highly differentiated endocrine cells and directly secretes into the blood circulation or tissue fluid to act as information transmission. It influences the physiological functions of the human body by controlling the metabolic processes of multiple tissue cells. Monitoring the levels of lipid hormone is of great importance for maintaining human health. The electrochemical sensor is considered as an ideal tool to detect lipid hormone owing to its advantages such as quick response, convenience and low economic costs. In recent 3 years, researchers have developed various electrochemical sensors for the detection of lipid hormone to improve their sensitivity or selectivity. The use of nanomaterials (such as carbon nanomaterials, precious metal and polymer) is a key research object and a breakthrough for improving the sensing performance of electrochemical sensors for detection of lipid hormone. This paper reviews and discusses the basic principle, nanomaterials, actuality and future development trend of electrochemical sensors for the detection of lipid hormone in the past 3 years.