Monitoring H₂O₂on the Surface of Single Cells with Liquid Crystal Elastomer Microspheres

Abstract

Live‐imaging of signaling molecules released from living cells is a fundamental challenge in life sciences. Herein, we synthesized liquid crystal elastomer microspheres functionalized with horse‐radish peroxidase (LCEM‐HRP), which can be immobilized directly on the cell membrane to monitor real‐time release of H2O2 at the single‐cell level. LCEM‐HRP could report H2O2 through a concentric‐to‐radial (C‐R) transfiguration, which is due to the deprotonation of LCEM‐HRP and the break of inter or intra‐chain hydrogen bonding in LCEM‐HRP caused by HRP‐catalyzed reduction of H2O2. The level of transfiguration of LCEM‐HRP revealed the different amounts of H2O2 released from cells. The estimated detection sensitivity was ≈2.2×10−7 μm for 10 min of detection time. The cell lines and cell–cell heterogeneity was explored from different configurations. LCEM‐HRP presents a new approach for in situ real‐time imaging of H2O2 release from living cells and can be the basis for seeking more advanced chemical probes for imaging of various signaling molecules in the cellular microenvironment.

In Situ Monitoring of Hydrogen Peroxide Released from Living Cells Using a ZIF-8-Based Surface-Enhanced Raman Scattering Sensor

“…3−6 H 2 O 2 can also easily transfer across plasma membranes from living cells, involving in transmembrane redox signaling processes. 4,7 Consequently, establishing an approach for sensitive and real-time monitoring of H 2 O 2 secreted from living cells is not only of great importance for early diagnosis but also for understanding the mechanism of membrane diffusion of H 2 O 2 and the behavior among cells. 7,8 To date, various analytical techniques were applied, such as fluorescence, electrochemistry, chemiluminescence, and so on, for the detection of H 2 O 2 .…”

“…4,7 Consequently, establishing an approach for sensitive and real-time monitoring of H 2 O 2 secreted from living cells is not only of great importance for early diagnosis but also for understanding the mechanism of membrane diffusion of H 2 O 2 and the behavior among cells. 7,8 To date, various analytical techniques were applied, such as fluorescence, electrochemistry, chemiluminescence, and so on, for the detection of H 2 O 2 . 9−13 Despite important progress, several factors hamper their widespread use, such as relatively long reaction time, low sensitivity, and self-interference.…”

Hypoxia‐Responsive Platinum Supernanoparticles for Urinary Microfluidic Monitoring of Tumors

“…[13] Microfluidic technology has become an important methodology for cell studies and disease detections. [14] Although they have great potential to provide a high sensitivity and simple readout for early disease detection, to date, PtNCs in conjunction with V-Chip to detect tumor biomarkers in blood have only been used in vitro. Therefore, we sought to exploit the inorganic catalytic activity of PtNCs to design an in vivo nanosensor platform that could directly read out disease status through the V-Chip.…”

A single-atom Cu–N2catalyst eliminates oxygen interference for electrochemical sensing of hydrogen peroxide in a living animal brain

“…16,17 Therefore, the information on the kinetics of H 2 O 2 would largely advance these studies. [18][19][20] Electrochemical oxidation or reduction of H 2 O 2 has been used to build a platform for H 2 O 2 sensing; 21 however, the oxidation of H 2 O 2 often bears interference from some reductive biomolecules, 22 and the reduction process always suffers from the interference from O 2 at almost all electrocatalysts. [23][24][25][26] Although HPRR is more favorable than ORR thermodynamically (Equations 1-2), it often proceeds more slowly than ORR in practical conditions due to the sluggish kinetics of HPRR and low mass transport efficiency of H 2 O 2 , 23,24 resulting in the occurrence of HPRR at more negative potentials than ORR, which makes it difficult to selectively sensing H 2 O 2 free from the interference from O 2 when potential-controlled amperometry is used.…”