The development of multifunctional nanomaterials capable of responding to environmental stimuli with distinct optical outputs has gained significant attention in the fields of sensing and security. This study presents a dual-mode pH sensor based on self-assembled chiral phosphorescent microflowers derived from L-/D-cysteine-functionalized gold nanoclusters (AuNCs). Upon integration with Cd²⁺ and controlled protonation via HNO₃, the AuNCs undergo hierarchical self-assembly into highly ordered microflower structures exhibiting both enhanced photoluminescence and amplified circular dichroism (CD) signals. The system demonstrates a reversible, pH-dependent ON/OFF switching behavior in emission intensity, enabling precise detection across a physiologically relevant pH range (pH 6.7–10.5). As the pH decreases, protonation of surface -NH₂ groups increases the net positive charge, promoting electrostatic attraction between adjacent clusters and facilitating dense aggregation. This results in maximum PL intensity at pH ≈ 6.7, followed by a decline due to excessive protonation-induced repulsion and structural collapse. Simultaneously, the CD signal at 375 nm diminishes with decreasing pH, indicating modulation of chiral environment within the assembly. The linear correlation between pH and both PL intensity and CD amplitude confirms the system’s suitability for quantitative dual-channel sensing. Unlike conventional single-parameter probes, this dual-mode approach allows for built-in self-calibration, reducing errors caused by external fluctuations such as temperature or excitation source drift.SSR1 Antibody medchemexpress Furthermore, the system enables robust information encryption through dynamic control of luminescence.Mucin 1 Antibody In stock Patterns imprinted with microflower suspension remain invisible under ambient light but are revealed under UV illumination (365 nm), forming a secure, non-reproducible visual code.PMID:34732351 The encrypted data can be erased using acidic vapor (HCl) and restored via basic vapor (NH₃), achieving repeatable, non-destructive cycling over multiple iterations without degradation. Time-lapse imaging confirms rapid response—within seconds—demonstrating real-time switchability. The reversibility is attributed to the dynamic nature of coordination and electrostatic interactions, which are fully reversible upon neutralization. These features make the platform ideal for anti-counterfeiting applications in high-value documents, pharmaceutical packaging, and digital authentication systems. The use of gaseous stimuli instead of liquid reagents enhances portability and stability, offering practical advantages for field deployment. Overall, this work establishes a new paradigm for intelligent nanomaterials that combine molecular chirality, tunable emission, and environmental responsiveness. It not only advances the fundamental understanding of supramolecular chiral amplification in metal nanoclusters but also provides a scalable, reliable, and reusable platform for next-generation smart sensors and secure information technologies.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
