Development of a borondipyrromethene-based Zn2+ fluorescent probe: solvent effects on modulation sensing ability

Area of Science:

• Analytical Chemistry
• Chemical Sensing
• Fluorescent Probes

Background:

• Zinc ions (Zn2+) play crucial roles in biological processes.
• Developing selective and sensitive fluorescent probes for Zn2+ is essential for biological research.
• Existing probes may face challenges with selectivity or sensitivity in complex biological environments.

Purpose of the Study:

• To design and synthesize a novel borondipyrromethene-based fluorescent probe, BODPAQ.
• To investigate the sensing mechanism and performance of BODPAQ for Zn2+ detection.
• To evaluate the influence of buffer composition on the probe's sensitivity and selectivity.

Main Methods:

• Synthesis of the BODPAQ fluorescent probe.
• Spectroscopic analysis (fluorescence emission) for Zn2+ detection.
• Investigation of probe response in different buffer solutions (MOPS, citrate-phosphate) and solvent compositions (acetonitrile).
• Evaluation of sensing mechanisms including Photoinduced Electron Transfer (PET) and Intramolecular Charge Transfer (ICT).

Main Results:

• BODPAQ exhibits high selectivity for Zn2+ with a significant fluorescence enhancement and hypsochromic shift.
• The probe operates via combined PET and ICT inhibition mechanisms, enabling ratiometric and turn-on fluorescence detection.
• BODPAQ's sensitivity to Zn2+ is highly dependent on buffer composition, with optimal sensitivity observed in 50% acetonitrile/MOPS buffer.
• No response to Zn2+ was observed in citrate-phosphate buffer.

Conclusions:

• BODPAQ is a promising fluorescent probe for selective Zn2+ detection.
• The probe's performance is modulated by buffer conditions, highlighting the importance of environmental factors in chemical sensing.
• Further studies are warranted to explore BODPAQ's utility in biological systems with optimized buffer conditions.