Surface organization of aptamers via diazonium grafting: A key parameter in label-free electrochemical sensing

The spatial arrangement of biorecognition molecules on the sensor surface plays a critical role in determining the performance of electrochemical biosensors. In this work, we report a covalent and tunable immobilization strategy using aryl diazonium chemistry to functionalize carbon electrodes with...

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Main Authors: Teodora Lupoi, Bogdan Feier, Florence Geneste, Cecilia Cristea, Yann R. Leroux
Format: Article
Language:English
Published: Elsevier 2025-09-01
Series:Electrochemistry Communications
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Online Access:http://www.sciencedirect.com/science/article/pii/S1388248125001390
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author Teodora Lupoi
Bogdan Feier
Florence Geneste
Cecilia Cristea
Yann R. Leroux
author_facet Teodora Lupoi
Bogdan Feier
Florence Geneste
Cecilia Cristea
Yann R. Leroux
author_sort Teodora Lupoi
collection DOAJ
description The spatial arrangement of biorecognition molecules on the sensor surface plays a critical role in determining the performance of electrochemical biosensors. In this work, we report a covalent and tunable immobilization strategy using aryl diazonium chemistry to functionalize carbon electrodes with ethynyl groups protected by trimethylsilyl (TMS) or triisopropylsilyl (TIPS) moieties. After deprotection, an azide-modified aptamer (APT) specific to diclofenac (DCF) was immobilized via copper-catalyzed azide–alkyne cycloaddition (CuAAC). Although the TMS and TIPS groups differ in size by only 1.7 Å, this small variation significantly influenced APT spacing and sensor performance. The TIPS-based sensor displayed a nearly fourfold increase in signal response compared to the TMS-based counterpart, achieving a limit of detection of 17.95 μM. These results underscore the importance of nanoscale molecular design in optimizing label-free aptasensor sensitivity.
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institution Kabale University
issn 1388-2481
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publishDate 2025-09-01
publisher Elsevier
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series Electrochemistry Communications
spelling doaj-art-adfaec58249b4d99bc2d6d663f3d2d812025-08-20T03:46:45ZengElsevierElectrochemistry Communications1388-24812025-09-0117810800010.1016/j.elecom.2025.108000Surface organization of aptamers via diazonium grafting: A key parameter in label-free electrochemical sensingTeodora Lupoi0Bogdan Feier1Florence Geneste2Cecilia Cristea3Yann R. Leroux4Univ Rennes, CNRS, ISCR, UMR 6226, F-35000 Rennes, France; “Iuliu Hatieganu” University of Medicine and Pharmacy, Faculty of Pharmacy, Department of Analytical Chemistry, 400349 Cluj-Napoca, Romania“Iuliu Hatieganu” University of Medicine and Pharmacy, Faculty of Pharmacy, Department of Analytical Chemistry, 400349 Cluj-Napoca, RomaniaUniv Rennes, CNRS, ISCR, UMR 6226, F-35000 Rennes, France“Iuliu Hatieganu” University of Medicine and Pharmacy, Faculty of Pharmacy, Department of Analytical Chemistry, 400349 Cluj-Napoca, RomaniaUniv Rennes, CNRS, ISCR, UMR 6226, F-35000 Rennes, France; Corresponding author.The spatial arrangement of biorecognition molecules on the sensor surface plays a critical role in determining the performance of electrochemical biosensors. In this work, we report a covalent and tunable immobilization strategy using aryl diazonium chemistry to functionalize carbon electrodes with ethynyl groups protected by trimethylsilyl (TMS) or triisopropylsilyl (TIPS) moieties. After deprotection, an azide-modified aptamer (APT) specific to diclofenac (DCF) was immobilized via copper-catalyzed azide–alkyne cycloaddition (CuAAC). Although the TMS and TIPS groups differ in size by only 1.7 Å, this small variation significantly influenced APT spacing and sensor performance. The TIPS-based sensor displayed a nearly fourfold increase in signal response compared to the TMS-based counterpart, achieving a limit of detection of 17.95 μM. These results underscore the importance of nanoscale molecular design in optimizing label-free aptasensor sensitivity.http://www.sciencedirect.com/science/article/pii/S1388248125001390Controlled immobilizationClick-chemistryDiazonium graftingElectrochemical sensor
spellingShingle Teodora Lupoi
Bogdan Feier
Florence Geneste
Cecilia Cristea
Yann R. Leroux
Surface organization of aptamers via diazonium grafting: A key parameter in label-free electrochemical sensing
Electrochemistry Communications
Controlled immobilization
Click-chemistry
Diazonium grafting
Electrochemical sensor
title Surface organization of aptamers via diazonium grafting: A key parameter in label-free electrochemical sensing
title_full Surface organization of aptamers via diazonium grafting: A key parameter in label-free electrochemical sensing
title_fullStr Surface organization of aptamers via diazonium grafting: A key parameter in label-free electrochemical sensing
title_full_unstemmed Surface organization of aptamers via diazonium grafting: A key parameter in label-free electrochemical sensing
title_short Surface organization of aptamers via diazonium grafting: A key parameter in label-free electrochemical sensing
title_sort surface organization of aptamers via diazonium grafting a key parameter in label free electrochemical sensing
topic Controlled immobilization
Click-chemistry
Diazonium grafting
Electrochemical sensor
url http://www.sciencedirect.com/science/article/pii/S1388248125001390
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AT florencegeneste surfaceorganizationofaptamersviadiazoniumgraftingakeyparameterinlabelfreeelectrochemicalsensing
AT ceciliacristea surfaceorganizationofaptamersviadiazoniumgraftingakeyparameterinlabelfreeelectrochemicalsensing
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