Real‐Time Cellular Cytochrome C Monitoring through an Optical Microfiber: Enabled by a Silver‐Decorated Graphene Nanointerface

Abstract

The translocation of cytochrome c (cyt c) from mitochondria and out of cell is an important signal of cell apoptosis. Monitoring this process extracellularly without invasion and cytotoxicity to cells is of great importance to understand certain diseases at the cellular level; however, it requires sensors with ultrahigh sensitivity and miniature size. This study reports an optical microfiber aptasensor with a silver‐decorated graphene (Ag@RGO) nanointerface for real‐time cellular cyt c monitoring. Owing to an interfacial sensitization effect coupled with the plasmonic electromagnetic enhancement of silver nanoparticles and chemical enhancement of graphene platforms, which enhances the energy density on microfiber surface obviously, the lowest limit of detection achieved is 6.82 × 10−17 m, which is approximately five orders of magnitude lower than those of existing methods. This microfiber successfully detects the ultralow concentrations of cyt c present during the initial stage of apoptosis in situ. As the microfiber functionalized by Ag@RGO nanointerface can be varied to meet any specific detection objective, this work opens up new opportunities to quantitatively monitor biological functions occurring at the cellular level.

Mitochondria-targeted antioxidant therapy for an animal model of PCOS-IR

“…Although the detection of Cyt C was not based on the total protein, it was noted that detecting total Cyt C protein has been reported in several studies; for example, Eleftheriadis et al ( 40 ) demonstrated that serum Cyt C levels may be a biomarker for mitochondrial and cellular damage. In addition, Li et al ( 41 ) measured Cyt C levels via an optical microfiber, and a study by Radhakrishnan et al ( 42 ) used an ELISA approach to determine plasma Cyt C levels. Overall, although the qualification of total Cyt C levels cannot reflect programmed cell death, it is only the way for reflecting the early event of apoptosis.…”

3D nanointerface enhanced optical microfiber for real-time detection and sizing of single nanoparticles

“…The interface functionalization of the optical microfiber was carried out following our previous work [32] with minor modifications. The typical synthesis process please see the Experimental Details in the Supplementary data.…”

Micro-/Nanofiber Optics: Merging Photonics and Material Science on Nanoscale for Advanced Sensing Technology

“…Enabled by the microfluidic channel (Figure 12B), one can monitor the immunoassay in real time, and the sensor can be reused for at least 10 cycles without significant losses in sensitivity. Recently, relying on an interfacial sensitization effect coupled with the plasmonic electromagnetic enhancement of silver nanoparticles and chemical enhancement of graphene platforms, Li et al demonstrated an optical microfiber aptasensor (Figures 11D-11F) with the lowest limit of detection of 6.82 3 10 À17 M, which is approximately five orders of magnitude lower than those of existing methods (Li et al, 2018a).…”