Magnetocatalytic Graphene Quantum Dots Janus Micromotors for Bacterial Endotoxin Detection

• Published in: Angewandte Chemie International Edition 2017-06, Vol.56 (24), p.6957-6961
• Main Authors: Jurado‐Sánchez, Beatriz, Pacheco, Marta, Rojo, Jaime, Escarpa, Alberto
• Format: Article
• Language: English
• Subjects: Actuation; Bacteria; Biosensing Techniques; Boronic Acids - chemistry; bubble propulsion; Catalysis; Encapsulation; Endotoxins; Equipment Design; Escherichia coli - chemistry; Fluorescence; Graphene; graphene quantum dots; Graphite - chemistry; Hydrogen peroxide; Integration; Iron; Iron oxides; Janus micromotors; Lab-on-a-chip; Lipopolysaccharides; Lipopolysaccharides - analysis; magnetic actuation; Magnetics; Micromotors; Nanoparticles; Platinum; Propulsion; Quantum dots; Quantum Dots - chemistry; Quenching; Receptors; Tags
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201701396

Magnetocatalytic hybrid Janus micromotors encapsulating phenylboronic acid (PABA) modified graphene quantum dots (GQDs) are described herein as ultrafast sensors for the detection of deadly bacteria endotoxins. A bottom‐up approach was adopted to synthesize an oil‐in‐water emulsion containing the GQDs along with a high loading of platinum and iron oxide nanoparticles on one side of the Janus micromotor body. The two different “active regions” enable highly efficient propulsion in the presence of hydrogen peroxide or magnetic actuation without the addition of a chemical fuel. Fluorescence quenching was observed upon the interaction of GQDs with the target endotoxin (LPS), whereby the PABA tags acted as highly specific recognition receptors of the LPS core polysaccharide region. Such adaptive hybrid operation and highly specific detection hold considerable promise for diverse clinical, agrofood, and biological applications and integration in future lab‐on‐chip technology. In the fast lane: Magnetocatalytic hybrid Janus micromotors encapsulating graphene quantum dots (GQDs) were developed as powerful mobile sensors for the detection of bacterial endotoxins. Two different active regions in the particles enabled bubble propulsion in the presence of hydrogen peroxide (see picture) or magnetic actuation without a chemical fuel. Fluorescence was quenched upon the interaction of the GQDs with the target endotoxin LPS.