A Wearable Optical Microfibrous Biomaterial with Encapsulated Nanosensors Enables Wireless Monitoring of Oxidative Stress

Abstract

In an effort to facilitate personalized medical approaches, the continuous and noninvasive monitoring of biochemical information using wearable technologies can enable a detailed understanding of an individual’s physiology. Reactive oxygen species (ROS) are a class of oxygen-containing free radicals which function in a wide range of biological processes. In wound healing applications, the continuous monitoring of ROS through a wearable diagnostics platform is essential for the prevention of chronicity and pathogenic infection. Here, a versatile one-step procedure is utilized to fabricate optical core-shell microfibrous textiles incorporating single-walled carbon nanotubes (SWCNTs) for the real-time optical monitoring of hydrogen peroxide concentrations in wounds. The environmentally sensitive and non-photobleachable fluorescence of SWCNTs enables continuous analyte monitoring without a decay in signal over time. The existence of multiple chiralities of SWCNTs emitting near-infrared fluorescence with narrow bandwidths allows a ratiometric signal readout invariant to the excitation source distance and exposure time. The individual fibers encapsulate the SWCNT nanosensors for at least 21 days without apparent loss in structural integrity. Moreover, the microfibrous textiles can be utilized to spatially resolve peroxide concentrations on a wound surface using a camera and can be integrated into commercial wound bandages without being altered or losing their optical properties.

Optical detection of pH changes in artificial sweat using near-infrared fluorescent nanomaterials

“…17,18 Furthermore, SWCNTs' unique properties like their size, biocompatibility upon functionalization, high chemical, thermal, and mechanical stability, and ease of chemical functionalization, can enhance sensing performance in biosensor platforms. [19][20][21][22] Because of the ultra-low background and high penetration depths in biological tissues, this region of the electromagnetic spectrum (tissue transparency window) is advantageous for detection and bioimaging applications. [23][24][25] Therefore, with nIR emission, SWCNTs have an advantage in optical sensing and imaging.…”

Guanine quantum defects in carbon nanotubes for biosensing

“…These unique properties make SWCNTs ideal building blocks for biomedical sensors and various applications in this field have already been demonstrated 3,6 . Biomolecules such as the important neurotransmitters dopamine 7 or serotonin 8 , riboflavin (vitamin B2) 9,10 , small metabolites for pathogen identification 11 , stress indicators like H2O2 12,13 or even peptides 14 and proteins [15][16][17] can be detected by SWCNT-based biosensors. Most of these sensors are designed by non-covalent surface chemistry with various kinds of polymers such as single-stranded DNA (ssDNA) or polyethylene glycols that create a corona phase around the SWCNT 3 .…”

Hyperspectral Counting of Multiplexed Nanoparticle Emitters in Single Cells and Organelles

“…25–28 SWCNTs exhibit intrinsic near-infrared (NIR) fluorescence emission that is photostable and environmentally-sensitive, 29–31 and are produced as a mixture of species, or chiralities, which can be identified by their chiral indices ( n,m ). 31 These advantageous properties have been leveraged to achieve multiplexed optical imaging 28, 32–34 and sensing 25–27, 35, 36 in addition to drug- and gene-delivery in live cells, 37, 38 plants, 39, 40 and animals. 34, 41 Such uses necessitate their accurate in situ characterization in biological systems, however, the 1-dimensional structure generally makes the direct visualization of individual SWCNTs with appropriate resolution difficult.…”