Design and Application of Fluorescent Probes Based on Flavonoid Dyes for Cysteine Detection.

As an important reactive sulfur species, cysteine plays a crucial role in maintaining the body's redox homeostasis and regulating protein function. Its content in organisms can serve as signaling molecules to directly or indirectly detect certain diseases. Therefore, based on the Michael addition mechanism, five flavonoid fluorescent probes HFL1-5 were designed and synthesized to detect cysteine.

Development of a Fluorescein-Based Probe with an "Off-On" Mechanism for Selective Detection of Copper (II) Ions and Its Application in Imaging of Living Cells.

Copper is a common metallic element that plays an extremely essential role in the physiological activities of living organisms. The slightest change in copper levels in the human body can trigger various diseases. Therefore, it is important to accurately and efficiently monitor copper ion levels in the human body.

A colorimetric probe for detection of Cu by the naked eye and application in test paper.

A novel colorimetric probe RP1 was synthesized using rhodamine derivatives and heterocyclic compounds for the purpose of detecting Cu . RP1 showed good selectivity, high sensitivity and affinity toward Cu over other competing ions in CH OH-H O (1/1, v/v) solution. Absorbance intensity showed a good linear fit between probe R1 and Cu over the concentration range 1-8 μM and the association constant was also calculated to be 1.

A Highly Selective "Turn-on" Fluorescent Probe for Detection of Fe in Cells.

A new "turn-on" fluorescent probe Py based on rhodamine and piperonaldehyde was designed and synthesized for detecting Fe in cells. The free probe Py was non-fluorescent. While only upon addition of Fe, the significant increase of the fluorescence and color were observed which could be visible directly by "naked-eye".

Novel rhodamine Schiff base type naked-eye fluorescent probe for sensing Fe and the application in cell.

Three rhodamine schiff-base type fluorescent sensors R1-R3 for detecting iron ion (Fe), 2-furanacrolein rhodamine hydrazone (R1), furfural rhodamine hydrazone (R2) and 2-furanacrolein rhodamine ethylenediamine (R3) have been synthesized by using rhodamine B derivatives and furan derivatives as staring materials. And their recognition abilities for Fe were studied by fluorescence spectroscopy. The result showed that R1 is a best selective probe for Fe over other metal ions in EtOH/HO (1:1, v/v) due to having 2-furanacrolein for unique space coordination structural.

Using molecular recognition of beta-cyclodextrin to determine molecular weights of low-molecular-weight explosives by MALDI-TOF mass spectrometry.

This study presents a novel method for determining the molecular weights of low molecular weight (MW) energetic compounds through their complexes of beta-cyclodextrin (beta-CD) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) in a mass range of 500 to 1700 Da, avoiding matrix interference. The MWs of one composite explosive composed of 2,6-DNT, TNT, and RDX, one propellant with unknown components, and 14 single-compound explosives (RDX, HMX, 3,4-DNT, 2,6-DNT, 2,5-DNT, 2,4,6-TNT, TNAZ, DNI, BTTN, NG, TO, NTO, NP, and 662) were measured. The molecular recognition and inclusion behavior of beta-CD to energetic materials (EMs) were investigated.