Rational Design of Conjugated Polymer Supramolecules with Tunable Colorimetric Responses

Abstract

Polydiacetylenes (PDAs), a family of highly π‐conjugated polymers, have unique characteristics associated with their ability to self‐assemble. Disruption of the extensively delocalized enyne backbones of molecularly ordered PDA sidechains induces a blue‐to‐red color change, which has been elegantly applied in the design of chemosensors. Recently, colorimetrically reversible PDAs have received significant attention, not only to gain a better understanding of the fundamentals of PDA chromism, but also to develop methodologies to overcome limitations associated with their colorimetrically irreversible counterparts. In this article, recent progress made in the field of colorimetrically tunable (reversible, stable, or sensitive) PDAs is described. Major emphasis is given to rational design strategies developed in our group. Relevant mechanistic investigations, a diagnostic method to test colorimetric reversibility, as well as future challenges in this area will be also discussed.

Dual‐Targeting Lactoferrin‐Conjugated Polymerized Magnetic Polydiacetylene‐Assembled Nanocarriers with Self‐Responsive Fluorescence/Magnetic Resonance Imaging for In Vivo Brain Tumor Therapy

“…The red fl uorescence resulted from the structural perturbations of PCDA molecules during the cell uptake reaction of Lf-PDNCs because no fl uorescence molecules were conjugated to the carriers, The ene-yne-conjugated backbone in the PCDA would bear high strain under the uptake process of PDNCs to the tumor cells that was caused by plasma membrane and the low pH value in the endosome. [ 17 ] Without loading or labeling fl uorescence molecules, the selfresponsive colorimetric change in the PDNCs can be used for intracellular traffi cking and furthermore as imaging-guided tumor treatment, which is an important characteristic and advantage of the PDNCs. We believed that this is the fi rst report to demonstrate that the PDNCs constructed with SPIO/PCDA unit micelles can display self-responsive color change upon cellular uptake.…”

Colorimetric detection of DNA, small molecules, proteins, and ions using unmodified gold nanoparticles and conjugated polyelectrolytes

“…This colorimetric "readout" avoids the relative complexity inherent in optical imaging/detection methodologies and thus may prove suitable for point-of-care and developing world applications (9)(10)(11)(12). Examples for the covalently modified nanoparticles include the work of Mirkin and collaborators, who pioneered the use of gold nanoparticle-DNA conjugates (22,23) for the sensitive detection of DNA and proteins (24)(25)(26)(27).…”

“…old nanoparticle colorimetric biosensors have seen significant applications in diagnostics, environmental monitoring, and antibioterrorism supporting unaided, visual readout (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Commonly, the relevant nanoparticles are covalently modified with either a probe DNA or an aptamer such that hybridization (13)(14)(15)(16) or aptamer-target interactions (17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27), for example the scanometric method developed by Mirkin (25), which is a very sensitive and specific tool, crosslink them, inducing aggregation.…”

Role of Gel to Fluid Transition Temperatures of Polydiacetylene Vesicles with 10,12-Pentacosadiynoic Acid and Cholesterol in Their Thermochromisms

“…[36][37][38][39] Regarding factors affecting conformation change in the π-bond, head group interactions, arising from hydrogen bonds/lateral stacking between aromatic rings or the flexibility of head groups, were suggested to play important roles. 30,[33][34][35]40 Meanwhile, melting of the unreacted monomers was also suggested to be a factor for the conformation change of the backbone. 41 On the other hand, it is little known how deeply the characteristics of selfassembled bilayers (in case of vesicles) or films of the polydiacetylenes connected with the conformation change of the backbone, affecting the colorimetric transitions.…”