Maurice Retout

University of California, San Diego

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Jesse V. Jokerst

University of California, San Diego

Zhicheng Jin

University of California, San Diego

Wonjun Yim

Massachusetts Institute of Technology

Gilles Bruylants

Université Libre de Bruxelles

Ivan Jabin

Université Libre de Bruxelles

Jiajing Zhou

Sichuan University

Matthew N. Creyer

University of California, San Diego

Yu‐Ci Chang

University of California, San Diego

Anthony J. O’Donoghue

University of Montana

Bryan Gosselin

Université Libre de Bruxelles

Cooperative Institutions

Robert Bosch (Germany)

University of California, San Diego

Université Libre de Bruxelles

Chinese Academy of Sciences

Centre National de la Recherche Scientifique

University of Chinese Academy of Sciences

University of California System

Shandong University

Sun Yat-sen University

Peking University

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A Charge‐Switchable Zwitterionic Peptide for Rapid Detection of SARS‐CoV‐2 Main Protease

Angewandte Chemie International Edition (2021)

Zhicheng Jin Yash Mantri Maurice Retout Yong Cheng Jiajing Zhou

Abstract The transmission of SARS‐CoV‐2 coronavirus has led to the COVID‐19 pandemic. Nucleic acid testing while specific has limitations for mass surveillance. One alternative is the main protease (M pro ) due to its functional importance in mediating the viral life cycle. Here, we describe a combination of modular substrate and gold colloids to detect M pro via visual readout. The strategy involves zwitterionic peptide that carries opposite charges at the C‐/N‐terminus to exploit the specific recognition by M pro . Autolytic cleavage releases a positively charged moiety that assembles the nanoparticles with rapid color changes ( t <10 min). We determine a limit of detection for M pro in breath condensate matrices <10 nM. We further assayed ten COVID‐negative subjects and found no false‐positive result. In the light of simplicity, our test for viral protease is not limited to an equipped laboratory, but also is amenable to integrating as portable point‐of‐care devices including those on face‐coverings.

Coronavirus

10.1002/anie.202112995

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Citations (61)

Single-atom Transistors for classical computing

arXiv (Cornell University) (2017)

Huu Chuong Nguyën Maurice Retout Gildas Lepennetier

In this review, we present an overview of four proof-of-concept of single-atom transistors based on four technologies : Atom doping, Single electron transistors, Single-atom metallic wire and Multilevel atomic-scale switching. Techniques and methods to build these transistors are described as such as the theory behind their mechanisms.

10.48550/arxiv.1701.05543

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Citations (1)

Gold–Silver Core–Shell Nanoparticle Crosslinking Mediated by Protease Activity for Colorimetric Enzyme Detection

Langmuir (2022)

Matthew N. Creyer Zhicheng Jin Maurice Retout Wonjun Yim Jiajing Zhou

Plasmonic nanoparticles produce a localized surface plasmon resonance (LSPR) under optical excitation. The LSPR of nanoparticles can shift in response to changes in the local dielectric environment and produce a color change. This color change can be observed by the naked eye due to the exceptionally large extinction coefficients (108–1011 M–1 cm–1) of plasmonic nanoparticles. Herein, we investigate the optical shifts (i.e., color change) of three unique gold–silver core–shell nanoparticle structures in response to changes in their dielectric environment upon nanoparticle aggregation. Aggregation is induced by a cysteine-containing peptide that has a sulfhydryl near its N and C termini, which crosslinks nanoparticles. Furthermore, we demonstrate that adding proline spacers between the cysteines impacts the degree of aggregation and, ultimately, the color response. Using this information, we construct a colorimetric enzyme assay, where the signal produced from nanoparticle aggregation is modulated by proteolysis. The degree of aggregation and the resulting optical shift can be correlated with enzyme concentration with high linearity (R2 = 0.998). Overall, this study explores the optical properties of gold–silver core–shell nanoparticles in a dispersed vs aggregated state and leverages that information to develop an enzyme sensor with a spectral LOD of 0.47 ± 0.09 nM.

Plasmonic Nanoparticles

Naked eye

Nanosensor

10.1021/acs.langmuir.2c02219

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Citations (14)

Ligation of Gold Nanoparticles with Self-Assembling, Coiled-Coil Peptides

The Journal of Physical Chemistry B (2023)

Matthew N. Creyer Maurice Retout Zhicheng Jin Wonjun Yim Jesse V. Jokerst

The surface of gold nanoparticles (AuNPs) can be conjugated with a wide range of highly functional biomolecules. A common pitfall when utilizing AuNPs is their tendency to aggregate, especially when their surface is functionalized with ligands of low molecular weight (no steric repulsion) or ligands of neutral charge (no electrostatic repulsion). For biomedical applications, AuNPs that are colloidally stable are desirable because they have a high surface area and thus reactivity, resist sedimentation, and exhibit uniform optical properties. Here, we engineer the surface of AuNPs so that they remain stable when decorated with coiled-coil (CC) peptides while preserving the native polypeptide properties. We achieve this by using a neutral, mixed ligand layer composed of lipoic acid poly(ethylene glycol) and lipoic acid poly(ethylene glycol) maleimide to attach the CCs. Tuning the surface fraction of each component within the mixed ligand layer also allowed us to control the degree of AuNP labeling with CCs. We demonstrate the dynamic surface properties of these CC-AuNPs by performing a place-exchange reaction and their utility by designing an energy-transfer-based caspase-3 sensor. Overall, this study optimizes the surface chemistry of AuNPs to quantitatively present functional biomolecules while maintaining colloid stability.

Biomolecule

Surface Modification

Surface charge

Maleimide

10.1021/acs.jpcb.3c02099

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Limits of thiol chemistry revealed by quantitative analysis of mixed layers of thiolated-PEG ligands grafted onto gold nanoparticles

Journal of Colloid and Interface Science (2019)

Maurice Retout Emilio Brunetti Hennie Valkenier Gilles Bruylants

Thiol

Surface Modification

Carboxylate

Alkyne

10.1016/j.jcis.2019.09.047

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Citations (22)

Ultrastable Silver Nanoparticles for Rapid Serology Detection of Anti-SARS-CoV-2 Immunoglobulins G

Analytical Chemistry (2022)

Bryan Gosselin Maurice Retout Raphaël Dutour Ludovic Troian‐Gautier Robin Bevernaegie

Dipstick assays using silver nanoparticles (AgNPs) stabilized by a thin calix[4]arene-based coating were developed and used for the detection of Anti-SARS-CoV-2 IgG in clinical samples. The calixarene-based coating enabled the covalent bioconjugation of the SARS-CoV-2 Spike Protein via the classical EDC/sulfo-NHS procedure. It further conferred remarkable stability to the resulting bioconjugated AgNPs, as no degradation was observed over several months. In comparison with lateral-flow immunoassays (LFIAs) based on classical gold nanoparticles, our AgNP-based system constitutes a clear step forward, as the limit of detection for Anti-SARS-CoV-2 IgG was reduced by 1 order of magnitude and similar signals were observed with 10 times fewer particles. In real clinical samples, the AgNP-based dipstick assays showed impressive results: 100% specificity was observed for negative samples, while a sensitivity of 73% was determined for positive samples. These values match the typical sensitivities obtained for reported LFIAs based on gold nanoparticles. These results (i) represent one of the first examples of the use of AgNP-based dipstick assays in the case of real clinical samples, (ii) demonstrate that ultrastable calixarene-coated AgNPs could advantageously replace AuNPs in LFIAs, and thus (iii) open new perspectives in the field of rapid diagnostic tests.

Bioconjugation

Silver nanoparticle

10.1021/acs.analchem.2c00870

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Citations (20)

Goldilocks Energy Minimum: Peptide-Based Reversible Aggregation and Biosensing

ACS Applied Materials & Interfaces (2023)

Wonjun Yim Maurice Retout Amanda A. Chen Chuxuan Ling Lubna Amer

Colorimetric biosensors based on gold nanoparticle (AuNP) aggregation are often challenged by matrix interference in biofluids, poor specificity, and limited utility with clinical samples. Here, we propose a peptide-driven nanoscale disassembly approach, where AuNP aggregates induced by electrostatic attractions are dissociated in response to proteolytic cleavage. Initially, citrate-coated AuNPs were assembled via a short cationic peptide (RRK) and characterized by experiments and simulations. The dissociation peptides were then used to reversibly dissociate the AuNP aggregates as a function of target protease detection, i.e., main protease (Mpro), a biomarker for severe acute respiratory syndrome coronavirus 2. The dissociation propensity depends on peptide length, hydrophilicity, charge, and ligand architecture. Finally, our dissociation strategy provides a rapid and distinct optical signal through Mpro cleavage with a detection limit of 12.3 nM in saliva. Our dissociation peptide effectively dissociates plasmonic assemblies in diverse matrices including 100% human saliva, urine, plasma, and seawater, as well as other types of plasmonic nanoparticles such as silver. Our peptide-enabled dissociation platform provides a simple, matrix-insensitive, and versatile method for protease sensing.

10.1021/acsami.3c09627

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Citations (4)

Modification of Surfaces with Calix[4]arene Diazonium Salts

Physical chemistry in action (2022)

Ludovic Troian‐Gautier Alice Mattiuzzi Pascale Blond Maurice Retout Gilles Bruylants

Nanomaterials

Surface Modification

10.1007/978-3-031-04398-7_13

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Citations (2)

Peptide Amphiphile Mediated Co‐assembly for Nanoplasmonic Sensing

Angewandte Chemie International Edition (2022)

Zhicheng Jin Yi Li Ke Li Jiajing Zhou Justin Yeung

Aromatic interactions are commonly involved in the assembly of naturally occurring building blocks, and these interactions can be replicated in an artificial setting to produce functional materials. Here we describe a colorimetric biosensor using co-assembly experiments with plasmonic gold and surfactant-like peptides (SLPs) spanning a wide range of aromatic residues, polar stretches, and interfacial affinities. The SLPs programmed in DDD-(ZZ)

10.1002/anie.202214394

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Citations (14)

Peptide‐Conjugated Silver Nanoparticles for the Colorimetric Detection of the Oncoprotein Mdm2 in Human Serum

ChemPlusChem (2022)

Maurice Retout Bryan Gosselin Alice Mattiuzzi Indiana Ternad Ivan Jabin

Abstract Invited for this month's cover are the collaborating groups of Prof. Gilles Bruylants and Prof. Ivan Jabin, Université libre de Bruxelles, Belgium. The cover picture shows the principle of a colorimetric sensor, based on peptide‐conjugated silver nanoparticles, for the detection of the cancer biomarker Mdm2. The particles were functionalized via a recently developed strategy based on the use of calixarene diazonium salts. The calixarene‐based coating provides an unprecedented stability to the silver nanoparticles, enabling their use as colorimetric reporters for in vitro diagnostics. The cover was designed by I. Jabin. More information can be found in the Research Article by I. Jabin, G. Bruylants, and co‐workers .

Calixarene

Silver nanoparticle

Colorimetry

10.1002/cplu.202200043

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Citations (13)