Using green emitting pH-responsive nanogels to report environmental changes within hydrogels: a nanoprobe for versatile sensing

Abstract

Low concentrations of new stimuli-responsive blue-green-fluorescent nanogel probes within four different gels and stem cells reversibly report five different stimuli: cations, degradation, pH, temperature and tensile strain.

Highly swelling pH-responsive microgels for dual mode near infra-red fluorescence reporting and imaging

“…S1A (ESI †) shows that the Q values for PEA-MAA-5/5.5 are much higher than those for our earlier (non-NIR) probe particles. 7,41 The zeta potential (z) was pH-responsive ( Fig. S2C, ESI †) and decreased from À48 mV (at pH 7.4) to À29 mV (at pH 4.5).…”

“…Fluorescent reporting and imaging are invaluable tools for remotely studying complex environments such as those within gels and the body. [1][2][3][4][5][6][7] Fluorescence-based technologies provide relatively simple and inexpensive operating procedures whilst delivering real-time imaging and diagnostic data 8,9 with high sensitivity, 10,11 low background noise 12 and potentially low-cost imaging reagents. 13,14 The reporter probes studied to date include organic dyes, 15 uorescent dots, 16 plasmonic nanomaterials, 17 uorescent proteins 18 and upconverting nanoparticles.…”

“…We recently investigated uorescent probes that used shortwavelength excitation and emission. 7,41 Short-wavelengths limit applications of such probes as a result of autouorescence, 23 photo-toxicity 54 and poor light penetration depth. 55 The probes were also weakly swelling with particle volume swelling ratios (Q) < 6.…”

“…However, there are a lack of responsive MG systems that have both excitation and uorescent emission within the deeply penetrating NIR region. 7,41 The new NIR MG probes introduced here (Scheme 1) comprise poly(ethyl acrylate-co-methacrylic acid-co-divinylbenzene) (PEA-MAA-DVB) and the covalently linked, complementary, sulfo-cyanine ourophores Cy5 (donor) and Cy5.5 (acceptor). The MG probes are termed PEA-MAA-5/5.5.…”

Design and Synthesis of Core–Shell Microgels with One‐Step Clickable Crosslinked Cores and Ultralow Crosslinked Shells

“…[ 2–4,11–21 ] Indeed, by virtue of this broad tunability, multiresponsive pNIPAm microgels have found applications across many biomedical applications, including sensing, drug delivery, and diagnostics. [ 22–32 ]…”