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

Advancement in early diagnosis of polycystic ovary syndrome: biomarker-driven innovative diagnostic sensor

Polycystic ovary syndrome (PCOS) is a heterogeneous multifactorial endocrine disorder that affects one in five women around the globe. The pathology suggests a strong polygenic and epigenetic correlation, along with hormonal and metabolic dysfunction, but the exact etiology is still a mystery. The current diagnosis is mostly based on Rotterdam criteria, which resulted in a delayed diagnosis in most of the cases, leading to unbearable lifestyle complications and infertility. PCOS is not new; thus, constant efforts are made in the field of biomarker discovery and advanced diagnostic techniques. A plethora of research has enabled the identification of promising PCOS diagnostic biomarkers across hormonal, metabolic, genetic, and epigenetic domains. Not only biomarker identification, but the utilization of biosensing platforms also renders effective point-of-care diagnostic devices. Artificial intelligence also shows its power in modifying existing image-based analysis, even developing symptom-based prediction systems for the early diagnosis of this multifaceted disorder. This approach could affect the future management and treatment direction of PCOS, decreasing its severity and improving the reproductive life of women. The rationale of the current review is to identify the advancements in understanding the pathophysiology through biomarker discovery and the implementation of modern analytical techniques for the early diagnosis of PCOS.

Molecularly imprinted hydrogels embedded with two-dimensional photonic crystals for the detection of dexamethasone/betamethasone sodium phosphate

Dexamethasone sodium phosphate (DSP) and betamethasone sodium phosphate (BSP) imprinted hydrogels embedded with two-dimensional photonic crystals (2DPC) were developed as hormones-sensitive photonic hydrogel sensors with highly sensitive, selective, anti-interference and reproducible recognition capability. The DSP/BSP molecularly imprinted photonic hydrogels (denoted as DSP-MIPH and BSP-MIPH) can specifically recognize DSP/BSP by rebinding the DSP/BET molecules to nanocavities in the hydrogel network. This recognition is enabled by the similar shape, size, and binding sites of the nanocavities to the target molecules. The rebinding of hormones molecules causes the hydrogel to swell, resulting in a particle spacing increase of the embedded 2DPC of the hydrogel. The particle spacing increase can be used as sensing signal and can be acquired by simply measuring the Debye diffraction diameters of the photonic hydrogel sensor before and after exposure with a laser pointer and a ruler. The particle spacing increments of the DSP-MIPH and BSP-MIPH sensors linearly change when DSP and BSP concentrations changes within the ranges 0.025-1 μM, 10-100 μM, and 100-500 μM, and the limits of detection (LoD) are 21.8 nM for DSP and 12.6 nM for BSP, respectively. These photonic hydrogel sensors were successfully applied to the determination of DSP/BSP contents in the real pharmaceutical injections, providing an ideal strategy for the development of portable hormones sensors.

Toward At-Home and Wearable Monitoring of Female Hormones: Emerging Nanotechnologies and Clinical Prospects

Steroid hormones, especially progesterone (P4), estradiol (E2), and testosterone (T), are key bioactive regulators in various female physiological processes, including growth and development, ovulation, and the reproductive cycle, as well as metabolism and mental health. As lipophilic molecules produced in sex glands, these steroid female hormones can be transported through blood vessels into various body fluids such as saliva, sweat, and urine. However, the ultralow concentration of steroid hormones down to picomolar (pM) level necessitates great demands for ultrasensitive but low-cost analytic tools to implement accurate, point-of-care or even continuous monitoring in a user-friendly fashion. This review focuses on the latest advances in materials and nanotechnologies to allow the rapid detection of female hormones at the pM level or below and the potentials in at-home and wearable hormone monitoring. We specifically summarize the optical and electrochemical strategies in this category, particularly those affording low cost and portable signal readout for at-home use. Furthermore, emerging flexible/wearable innovations are highlighted, which allow the continuous hormone cycle tracking in a noninvasive manner. The potential of these techniques is discussed to address the need for real-time acquisition of the hormone fluctuation, facilitating health monitoring at home. Lastly, we provide a comprehensive introduction to the prospects of female hormone monitoring in clinical diagnosis and treatment, from the perspective of gynecology and reproductive medicine clinicians.

Electropolymerization of poly(phenol red) on laser-induced graphene electrode enhanced adsorption of zinc for electrochemical detection

We present a highly sensitive and selective electrode of laser-induced graphene modified with poly(phenol red) (P(PhR)@LIG) for measuring zinc nutrition in rice grains using square wave anodic stripping voltammetry (SWASV). The physicochemical properties of P(PhR)@LIG were investigated with scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), Fourier infrared spectroscopy (FT-IR) and Raman spectroscopy. The modified electrode demonstrated an amplified anodic stripping response of Zn2+ due to the electropolymerization of P(PhR), which enhanced analyte adsorption during the accumulation step of SWASV. Under optimized parameters, the developed sensor provided a linear range from 30 to 3000 μg L-1 with a detection limit of 14.5 μg L-1. The proposed electrode demonstrated good reproducibility and good anti-interference properties. The sensor detected zinc nutrition in rice grain samples with good accuracy and the results were consistent with the standard ICP-OES method.

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.

Proximity hybridization regulated dual-mode ratiometric biosensor for estriol detection in pregnancy serum

Sensitive and accurate determination of estriol level is vastly significant for the fetal growth and development. Herein, we constructed a dual-mode ratiometric biosensor for estriol assay combining the competitive immunoreaction, proximity hybridization with a two-step resonance energy transfer (RET) strategy. Estriol antibody and goat anti-rabbit antibody labeled DNA probes (Ab1-DNA1-Pt NPs and Ab2-DNA2) both hybridized with silver nanoclusters labeled DNA strands (H1-Ag NCs). Thus, the formed proximity hybridization enabled the occurrence of fluorescence RET (FL-RET, as the primary RET) between Ag NCs (donor) and Pt NPs (acceptor), quenching FL intensity of Ag NCs (FL off). When target estriol existed, the competitive reaction of Ab1-DNA1-Pt NPs with estriol and Ab2-DNA2 avoided the proximity hybridization. Then, the estriol-dependent H1-Ag NCs quenched electrochemiluminescence (ECL) emission of CdS quantum dots (CdS QDs, ECL off), generating ECL-RET (as the second RET). Consequently, according to the reverse changes of FL and ECL responses, this sensor realized the quantification of estriol from 1 to 100 ng/mL. Moreover, satisfactory results were achieved while testing estriol in pregnancy serum specimens, suggesting that the system is promising for potential application in samples analysis.