Metal‐Bridged Graphene–Protein Supraparticles for Analog and Digital Nitric Oxide Sensing

Abstract

Self‐limited nanoassemblies, such as supraparticles (SPs), can be made from virtually any nanoscale components, but SPs from nanocarbons including graphene quantum dots (GQDs), are hardly known because of the weak van der Waals attraction between them. Here it is shown that highly uniform SPs from GQDs can be successfully assembled when the components are bridged by Tb3+ ions supplementing van der Waals interactions. Furthermore, they can be coassembled with superoxide dismutase, which also has weak attraction to GQDs. Tight structural integration of multilevel components into SPs enables efficient transfer of excitonic energy from GQDs and protein to Tb3+. This mechanism is activated when Cu2+ is reduced to Cu1+ by nitric oxide (NO)—an important biomarker for viral pulmonary infections and Alzheimer's disease. Due to multipronged fluorescence enhancement, the limit of NO detection improves 200 times reaching 10 × 10–12 m. Furthermore, the uniform size of SPs enables digitization of the NO detection using the single particle detection format resulting in confident registration of as few as 600 molecules mL−1. The practicality of the SP‐based assay is demonstrated by the successful monitoring of NO in human breath. The biocompatible SPs combining proteins, carbonaceous nanostructures, and ionic components provide a general path for engineering uniquely sensitive assays for noninvasive tracking of infections and other diseases.

Zero-Dimensional Carbon Nanomaterials for Fluorescent Sensing and Imaging

“…815 Fan et al coassembled superoxide dismutase with GQDs using Tb 3+ to obtain self-limiting nanocomponent superparticles, which can detect 10 × 10 −12 mol•L −1 of NO under the combined action of components such as combined proteins, carbon nanostructures, and ions, offering the possibility of highly sensitive and convenient detection of viral lung infections and Alzheimer's disease (Figure 31d). 816 To promote the specificity and adsorption capacity to sulfadimethoxine, Bunkooed et al developed the fluorescent sensor GQDs@PC@MIP by integrating GQDs and porous carbon into MIP. The fluorescence of the probe was quenched when sulfadimethoxine was bound to the selective recognition site, resulting in a quantitative analysis method; this layered composite nanofluorescent probe has been used to determine sulfadimethoxine in milk (Figure 32b).…”

Research Progress of Graphene and Its Derivatives towards Exhaled Breath Analysis

“…Inspired by self-limiting nano-components, Qu et al assembled graphene quantum dots (GQDs) and superoxide dismutase (SOD) into monodisperse superparticles (SPs) [ 59 ]. As shown in Figure 4 b, graphene quantum dots (GQDs) and superoxide dismutase (SOD) were assembled to synthesize GQD–Tb 3+ –SOD SPs, and were coated on a glass plate for NO sensing test.…”

“…Copyright (2021), used with permission from Elsevier. ( b ) Schematic diagram of the process of monodisperse superparticles (SPs) prepared by coordinating bridged graphene quantum dots (GQDs) and superoxide dismutase (SOD) using terbium ion as metal [ 59 ]. Copyright (2021), used with permission from Wiley.…”

Comprehensive exploration of long-wave emission carbon dots for brain tumor visualization

“…Carbon dots (CDs), typical zero-dimensional fluorescent materials, are predominantly comprised of an amorphous carbon network with a conjugated structure, usually with a size below 10 nm. 4 Their excellent luminescence characteristics have attracted countless scientific research studies 5 in catalytic sensing, 6 environmental monitoring, 7 and biomedical imagining. 8 However, conventional CDs emit short-wavelength green or blue fluorescence, which greatly limits their in-depth imagining applications.…”