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Selective detection of Selegiline in Parkinson's patient urine via CuAAC-mediated fluorescence quenching of Azide-modified carbon dots

Research Abstract
Selegiline, a selective monoamine oxidase-B inhibitor used in Parkinson's disease treatment, requires accurate detection for therapeutic drug monitoring and optimal dosing. This study presents a novel fluorometric method for selegiline detection based on azide-modified carbon dots that selectively interact with selegiline's terminal alkyne group through copper-catalyzed azide-alkyne cycloaddition (CuAAC). This specific click chemistry reaction results in fluorescence quenching of the carbon dots. The detection mechanism and comprehensive characterization of the azide-modified carbon dots are thoroughly discussed, including their synthesis, optical properties, and interaction behavior with selegiline. The method exhibits excellent analytical performance with good linearity across a wide concentration range of (0.1–80.0 ng/mL) and demonstrates a low limit of detection of 0.041 ng/mL. A selective extraction methodology employing FMOC derivatization coupled with mixed-mode cation exchange (MCX) solid-phase extraction was developed to eliminate amine metabolites and biological interferents while preserving selegiline's tertiary amine structure for selective retention and purification. The method shows high selectivity against interferents and achieves excellent percentage recovery values reaching (96.0–97.0 %) when applied to urine samples. Most importantly, the method was successfully applied to urine samples from Parkinsonism patients, providing a non-invasive route for selegiline determination that offers significant advantages over traditional invasive sampling methods.

 
Research Authors
Ali O. Alqarni, Rayed Ali A. Alqahtani, Ashraf M. Mahmoud, Meshal H. Almabadi, Fatmah M. Alshareef, Mohamed N. Goda, Ramadan Ali, Al-Montaser Bellah H. Ali
Research Date
Research Journal
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Research Member
Research Pages
127051
Research Publisher
elsevier
Research Rank
Q1
Research Vol
347
Research Website
https://www.sciencedirect.com/science/article/pii/S1386142525013587
Research Year
2025

Preparation of 6, 8-Dithiooctanoic Acid-Functionalized Copper Nanoclusters with Near-Infrared Emission: Application for Determination of Melamine in Food Matrices

Research Authors
Yousef A. Bin Jardan, Aya M. Mostafa, James Barker, Almontaser Bellah H. Ali & Mohamed M. El-Wekil
Research Date
Research Journal
Journal of Cluster Science
Research Year
2025

Engineering sensitive ratiometric probe based on Tb@BNCDs and thiolated-protected AuNCs for melamine sensing via competitive coordination mechanism

Research Authors
Yousef A. Bin Jardan, Aya M. Mostafa, James Barker, Mohamed N. Goda, Almontaser Bellah H. Ali & Mohamed M. El-Wekil
Research Date
Research Journal
Microchimica Acta
Research Year
2025

Ultrasensitive detection of zineb using a CoMn-MOF/rGO molecularly imprinted electrochemical sensor

Research Abstract

Regulatory agencies have identified zineb (ZNB) as a potential health hazard due to its toxicological profile and environmental persistence. Therefore, establishing a highly selective and ultrasensitive method for ZNB detection is crucial for environmental monitoring, food safety assurance, and effective pesticide regulation enforcement. Herein, a selective electrochemical sensor was engineered based on a molecularly-imprinted polymer (MIP) film designed for targeted analyte recognition. The sensing platform integrates bimetallic cobalt–manganese metal–organic frameworks (CoMn-MOFs) with reduced graphene oxide (rGO) to enhance conductivity and surface activity. Initially, GO was synthesized and subsequently reduced to conductive rGO utilizing sodium borohydride via a modified Hummers’ method, forming a high-conductivity matrix for efficient electron transfer. Second, CoMn-MOFs were incorporated to significantly enhance the active surface area and facilitate electron transfer. A selective MIP layer was formed on the electrode surface via electro-polymerization, enabling precise molecular recognition of ZNB. The resulting MIP/rGO/CoMn-MOFs-modified glassy carbon electrode (GCE) exhibited excellent analytical performance, including a broad linear range (0.01–200 nM), a low LOD (4.0 pM), and high selectivity against potential interferents. When applied to real food and water samples, the sensor achieved high accuracy, with recoveries  ranging from 95.5% to 105.6% and RSDs between 1.87% and 4.00%. The method was validated using the standard addition technique, confirming its applicability for accurate ZNB quantification in complex food and water matrices. These findings validate the sensor’s potential as a practical, rapid, and environmentally friendly platform for monitoring ZNB residues in agricultural and environmental contexts.

Research Authors
Ramadan Ali, Hassabelrasoul Elfadil, Nizar Sirag, Reem Alshaman, Abdullah S. Albalawi, Nwaeam Albalawi, Amjad albalawi, Salma Alharbi, Alanoud Al-anzi, Shatha alatawi, Yusra Alhuaiti, Nawaf Aldwsari & Mohamed M. El-Wekil
Research Date
Research Journal
microchimica acta
Research Pages
469
Research Publisher
Springer
Research Rank
Q1
Research Vol
192
Research Website
https://doi.org/10.1007/s00604-025-07326-3
Research Year
2025

Integrating catalytic and fluorescence quenching strategies: A nanozyme-based platform for rutin sensing in complex matrices

Research Abstract

Rutin is a potent antioxidant with therapeutic value in managing vascular and inflammatory conditions. Its accurate quantification is critical for pharmaceutical quality control and food safety. In this study, rutin was employed as a template to construct surface molecularly imprinted magnetic nanozymes (MIPs@Fe3O4–CoNi). These nanozymes retained peroxidase-like activity, catalyzing the H2O2-driven transformation of non-fluorescent terephthalic acid into fluorescent 2-hydroxyterephthalic acid. Upon rutin binding, catalytic activity was suppressed, and the fluorescence signal was further quenched through static and inner-filter effects. This dual-signal suppression mechanism significantly enhanced sensor sensitivity. The developed sensing platform exhibited a low detection limit of 0.008 μM and a broad linear range. When applied to pharmaceutical tablets, human serum, and food samples, it achieved recovery rates between 97.5 % and 104.0 %, with RSDs of 2.57 %–4.00 %. These results confirm the method's reliability, precision, and practical applicability across diverse matrices.

Research Authors
Ramadan Ali a , Saad D. Alamri b , Bassam Alkhuli b , Turki A. Albalawi b , Abdullah H. Alqarni b , Waleed I. Albalawi b , Zamil A. Alorabi b , Areej S. Alatawi b , Afnan Almarwani b , Mohamed M. El-Wekil
Research Date
Research Journal
Talanta
Research Pages
128796
Research Publisher
ElSevier
Research Rank
Q1
Research Vol
297
Research Website
https://doi.org/10.1016/j.talanta.2025.128796
Research Year
2025

Switchable nanozyme-based colorimetric assay for protamine and heparin using silver citrate nanoparticles

Research Authors
Khalid Alhazzani, Ahmed Z. Alanazi, James Barker, Aya M. Mostafa, Hassabelrasoul Elfadil, Al-Montaser Bellah H. Ali,Mohamed M. El-Wekil
Research Date
Research Journal
Microchemical Journal
Research Year
2025
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