FeS 2 Grown Pencil Graphite as an In‐expensive and Non‐enzymatic Sensor for Sensitive Detection of Uric Acid in Non‐invasive Samples

Determination of Uric Acid in Artificial Saliva with Compact AMP3291 Reader and Au Nanoparticles Modified Electrode

Uric acid (UA) is a residual product of purines in the body and has been proposed as a valuable biomarker for Diabetes Mellitus, renal disorder, hypertension and preeclampsia. This work presents a sensing platform for nonenzymatic UA detection using a screen-printed electrode modified with gold nanoparticles (SPE-AuNps) operated with the compact and low-cost amperometric reader AMP3291. This laboratory-made instrument was designed using the analog front end LMP91000 and the microcontroller ESP32; the operational parameters like working potential, acquisition time and dynamic measuring range were configured for UA detection. The whole sensing system (AMP3291+ SPE-AuNps) was evaluated for nonenzymatic sensing of UA, showing a fast response time of 3.5 s, a sensitivity of 0.022 μA·μM−1, a linear range from 20 to 200 μM (R2 = 0.993) and a limit of detection of 11.91 μM. Throughout, a piece of commercial equipment was used for validation and noticeably the measurements with the AMP3291-based platform showed improved performance, indicating the feasibility of the developed instrument for UA monitoring and potentially for in situ decentralized applications. Finally, artificial saliva was used as model medium exhibiting interesting analytical parameters, encouraging to consider the reported system as a potentially valuable tool for monitoring UA for clinical applications in resource-limited settings.

Recent advancements in fabrication of nanomaterial based biosensors for diagnosis of ovarian cancer: a comprehensive review

Ovarian cancer is commonly diagnosed via determination of biomarkers like CA125, Mucin 1, HE4, and prostasin that can be present in the blood. However, there is a substantial need for less expensive, simpler, and portable diagnostic tools, both for timely diagnosis and management of ovarian cancer. This review (with 101 refs.) discusses various kinds of nanomaterial-based biosensors for tumor markers. Following an introduction into the field, a first section covers different kinds of biomarkers for ovarian cancer including CA125 (MUC16), mucin 1 (MUC1), human epididymis protein 4 (HE4), and prostasin. This is followed by a short overview on conventional diagnostic approaches. A large section is then presented on biosensors for determination of ovarian cancer, with subsections on optical biosensors (fluorimetric, colorimetric, surface plasmon resonance, chemiluminescence, electrochemiluminescence), on electrochemical sensors, molecularly imprinted sensors, paper-based biosensors, microfluidic (lab-on-a-chip) assays, chemiresistive and field effect transistor-based sensors, and giant magnetoresistive sensors. Tables are presented that give an overview on the wealth of methods and materials. A concluding section summarizes the current status, addresses current challenges, and gives an outlook on potential future trends. Graphical abstract Schematic representation of the review covering the advancements in the fabrication of various nanomaterial based biosensors for diagnosis of ovarian cancer.