confocal laser scanning microscope

IOPBA is a fluorescent probe that can be used for the detection and bioimaging of trivalent iron ions Fe ³⁺ and fluoride ions F ^- in living cells. IOPBA emits blue fluorescence in its native state, but upon the introduction of Fe ³⁺, it forms a Fe ³⁺-IOPBA π-complex, where Fe ³⁺ ions coordinate with two phenyl groups of IOPBA, resulting in fluorescence quenching. IOPBA returns to its free state and recovers its original fluorescence after F ^- sequesters Fe ³⁺ to form the more stable [FeF₆] ^3- and dissociates the Fe ³⁺-IOPBA complex. The excitation wavelength of IOPBA is 342 nm, and its emission wavelength is 458 nm .

Mem-pH is a ratiometric fluorescent probe used for measuring vesicular pH. Mem-pH inserts into the plasma membrane bilayer and localizes to the vesicular lumen, switching between its basic and acidic forms via protonation during vesicular acidification to enable ratiometric pH readout. In aqueous media, Mem-pH forms non-emissive aggregates through aggregation-induced quenching, and then depolymerizes and recovers its fluorescent activity upon binding to the plasma membrane. The excitation/emission wavelengths of the basic form of Mem-pH are 405/450-550 nm, while those of the acidic form are 488/500-700 nm .

HOTPy is a mitochondria-targeted fluorescent viscosity probe with aggregation-induced emission properties, which responds to microenvironmental viscosity. HOTPy can recognize the abnormal increase in mitochondrial viscosity and capture dynamic viscosity changes in acute alcoholic liver injury models at both cellular and in vivo levels. The maximum absorption peak of HOTPy in PBS solution is at 379 nm; its maximum emission peak reaches 611 nm in a high-viscosity glycerol system. HOTPy can be used for the research of acute alcoholic liver injury .

Dansyl-morpholine (DNS-M) is a Fluorescent probe for lipid droplet imaging, cancer cell discrimination, and real-time tracking of lipid droplet dynamics. As a solvatochromic probe with a donor-π-acceptor structure, it relies on hydrophobic interaction for its mechanism of action: its good lipophilicity, confirmed by an oil-water partition coefficient LogP = 2.35, allows it to rapidly penetrate cell membranes, and it specifically localizes to the hydrophobic core of lipid droplets; its fluorescence is strongly enhanced in the nonpolar environment of lipid droplets, while it emits very weak fluorescence in polar environments like PBS buffer, and it exhibits a bathochromic shift in emission wavelength with increasing solvent polarity. It has negligible cytotoxicity, with cell viability remaining over 95% after 24-hour incubation with 100 μM of the probe, and it possesses excellent photostability, retaining over 97% of initial fluorescence intensity after 60 continuous laser scans. For cell imaging applications, its excitation/emission wavelengths for lipid droplet labeling are Ex/Em = 405/480−540 nm, and in a simulative lipid environment O/W emulsion, it has an excitation wavelength of ~346 nm and emission wavelength of ~500 nm, giving a Stokes shift of 154 nm[1].

NtHzBtd is a fluorescent probe for detecting Fe ³⁺. NtHzBtd is applicable to the selective fluorescent detection of Fe ³⁺ ions and live cell imaging studies. NtHzBtd can selectively coordinate with Fe ³⁺ to form a 1:1 complex, triggering chelation enhanced quenching (CHEQ) and intramolecular charge transfer (ICT) processes, which result in fluorescence turn-off, thereby enabling sensitive detection of Fe ³⁺ and live cell fluorescence imaging. After binding to Fe ³⁺, NtHzBtd reduces fluorescence intensity, exhibits a rapid response property, with a limit of detection of 0.036 μM and a response time of approximately 55 s. The detection wavelengths are Ex/Em = 334/401 nm (solution system) .

TPE-2E N-oxide is a fluorescent probe used for hypoxia detection and tumor hypoxia imaging. Due to its active intramolecular motion, TPE-2E N-oxide shows no fluorescence in aqueous solution. In hypoxic environments, its N-oxide group undergoes two-electron reduction by CYP450 reductase and other heme protein reductases expressed under hypoxia, forming hydrophobic aggregates that trigger aggregation-induced emission through the restriction of intramolecular motion. TPE-2E N-oxide exhibits selective lipid droplet localization in cells. The absorption wavelength of TPE-2E N-oxide in dichloromethane is 313 nm; in a 99% hexane/dichloromethane mixed system, its excitation wavelength is 330 nm and emission wavelength is 460 nm. For in vitro cell imaging, excitation is performed at 405 nm, with an emission wavelength range of 430-560 nm .