Bio-nanocomposite based highly sensitive and label-free electrochemical immunosensor for endometriosis diagnostics application.

In this research, for the first time, a bio-nanocomposites based highly sensitive and label-free electrochemical immunosensor is reported with the aim of endometriosis diagnostics application. Multiwalled carbon nanotube and magnetite nanoparticle (MWCNT-Fe3O4) was dispersed in chitosan (CS) to fabricate a bio-nanocomposite to immobilize very monoclonal specific antibody (via cross-linking using glutaraldehyde) for selective electrochemical immuno-sensing of carbohydrate antigen 19-9 (CA19-9), a potential biomarker for endometriosis diagnostics. Well-characterized Anti-AbsCA19-9/CS-MWCNT-Fe3O4 immune-electrode fabricated on glassy carbon electrode (GCE) successfully detect CA 19-9 and exhibited a high sensitivity as (2.55 µA pg-1 cm-1), a detection limit of 0.163 pg mL-1, detection range from 1.0 pg mL-1 to 100 ng mL-1. Our fabricated electrochemical AbsCA19-9/CS-MWCNT-Fe3O4 immunosensor performed CA19-9 sensing in physiological range and at a very level which suggest it application for early-stage diagnostics, diseases monitoring, and optimization of therapy. To claim the clinical application, our sensor was tested using real samples and sensing performance was validated using enzyme-linked immune-sorbent assay (ELISA). The results of the studies projected AbsCA19-9/CS-MWCNT-Fe3O4 electrochemical CA19-9 immunosensor as a potential and affordable alternate of conventional techniques like ELISA. We believe that our fabricated sensor can be the plane of a disease's management program due to affordable, rapid, label-free, and sensitive detection of a targeted biomarker.

Detection of a novel glycodelin biomarker using electrochemical immunosensor for endometriosis.

Endometriosis is one of the important issues in women worldwide, which decreases the quality of women's lives in their reproductive age. The diagnosis of endometriosis is carried out by the invasive procedure, which is expensive and painful. In the last few decades, researchers have given more attention to constructing a suitable biomarker-based biosensor for semi/non-invasive diagnosis of endometriosis. As a result, glycodelin (GLY) was found as a promising biomarker because of its selectivity and sensitivity. To the best of our knowledge, it was the first study that reported the detection of GLY biomarker using an electrochemical immunosensor. Briefly, a label-free electrochemical immunosensing platform was constructed through in-situ surface modification of cysteamine layer and immobilisation of antibody (anti-GLY) with help of glutaraldehyde. The interaction between antigen and antibody was measured using square wave voltammetry (SWV). The SWV signal could decrease proportionally with the increasing GLY concentration ranging from 1 to 1000 ng mL-1 (R2 = 0.9981) and a detection limit (LOD) of 0.43 ng mL-1. Moreover, an immunosensor could exhibit high sensitivity, selectivity, long-term stability, reproducibility and regeneration. Accuracy of the immunosensor was compared with enzyme-linked immunosorbent assay (ELISA), and satisfying results were obtained. The detection of GLY biomarker may be a new possibility for endometriosis diagnosis.

Label-Free Electrochemical Immunosensor Based on One-Step Electrochemical Deposition of AuNP-RGO Nanocomposites for Detection of Endometriosis Marker CA 125.

Endometriosis is the third most prominent gynecological disorder. Cancer antigen 125 (CA 125) is the primary serum marker used for late-stage endometriosis diagnosis and management. Herein, we developed a label-free immunosensor for electrochemical detection of CA 125 for endometriosis blood serum samples. The sensor was fabricated by one-step electrochemical deposition of highly conductive gold nanoparticles (AuNPs) and reduced graphene oxide (RGO) nanocomposite, via one-step electrochemical deposition. This method involved in situ reduction of HAuCl3 and graphene oxide and increased electrocatalytic performance. Different analytical techniques confirmed the morphology and structure of the AuNP/RGO nanocomposite. In addition, the antibody (Ab) was immobilized on the modified electrode surface through the self-assembly monolayer. The square wave voltammetry method has been utilized to measure the interaction of Ab and antigen (Ag). The as-fabricated sensor demonstrates a dynamic linear range of 0.0001 → 300 U mL-1 and lower limit of detection is 0.000042 U mL-1 toward CA125 detection. The developed sensor provides acceptable stability, high selectivity, and reproducibility. The proposed immunosensor has been applied to the CA 125 detection in endometriosis patient blood samples, and the results confirm the reliability of the as-fabricated sensor that is further associated with the standard ELISA analysis. The AuNP/RGO-based sensor can be used as an excellent tool for future prospective clinical diagnostics applications.