Mercury Biosensors: Polydiacetylene–Liposome Microarrays for Selective and Sensitive Mercury(II) Detection (Adv. Mater. 36/2009)

Abstract

Polydiacetylene (PDA) liposome microarrays have been developed for selective and sensitive mercury detection. The sensors, reported by Jinsang Kim and co‐workers, are designed to produce red fluorescence emission upon binding with Hg2+; when the single‐stranded DNA aptamers on the microarray selectively wrap around the mercury ions, the resulting complexes repulse each other. The epoxy‐based PDA liposome design is an excellent universal platform that can be readily extended to other sensor designs.

Detection of Mercury(II) by Quantum Dot/DNA/Gold Nanoparticle Ensemble Based Nanosensor Via Nanometal Surface Energy Transfer

“…The filtered water was then mixed with the stock DNA/QD buffer solution in the ratio of 1:2 (v/v) to obtain the DNA/QD test solution. The sensitivity of the QD/DNA/Au/ river water system was checked after addition of various concentrations of Hg 2+ ions (0, 1,2,4,6,8,10,15,20,30,40,60,80,100,200, 500, and 1000 nM). The initial fluorescence intensity in the DNA/QD solution containing the river water was lower than that in the pure buffer solution (Figure 5a), which was believed to be ascribed to the fluorescence quenching of the QDs by the various environmental substances in the river water.…”

Organic Semiconductor–DNA Hybrid Assemblies

“…According to the literature, a specific sequence of thyminerich ssDNAs can be coordinated with mercury ions accompanied by a G-quadruplex or hairpin-shaped DNA conformation. [73,74] Hence, the abovementioned hybrid assemblies can be used as a probe of mercury ions. [75] Figure 7a illustrates the in situ PL images of the hybrid assemblies before and after interaction with the mercury ion solution.…”

Mussel-Inspired Universal Bioconjugation of Polydiacetylene Liposome for Droplet-Array Biosensors

“…Solid-state biosensor platforms have various advantages over solution-based counterparts, such as easy handling during washing and buffer exchange steps, stable long-term storage, high-throughput simultaneous multidetection, and good portability. − To build a solid-state sensor, a signal-generating unit should be firmly immobilized to a substrate, and a receptor molecule or a specific functional group should be chemically tethered to the signal-generating unit. These two conjugation steps require specific chemical modifications and optimization of the substrate, a signal-generating unit, and a receptor molecule. , …”

“…Polydiacetylene (PDA) is an attractive conjugated polymer for colorimetric and self-signaling sensory applications owing to its well-known mechanochromism. − When mechanically stressed by external stimuli, such as heat, − humidity, , metal ions, ,, chemicals, ,− and biological molecules, ,− PDA changes its color from blue to red owing to the resulting distortion of its conjugated yne–ene main chain. In addition to this colorimetric signal, PDA also provides an additional fluorescence-based detection scheme because the red-phase PDA emits red fluorescence, whereas the original blue phase has no emission.…”

“…We previously reported various PDA liposome-based microarrays as a highly sensitive, selective, and universal optical biosensor platform. ,, We designed PDA monomers having a functional head group such as N-hydroxysuccinimide-ester and epoxy , for (i) immobilization of the liposomes to an amino-functionalized surface (e.g., aminosilane-coated glass) and (ii) tethering of amine-containing specific receptors (e.g., DNA aptamers, peptides, and antibodies) to the liposome layer. However, these previous approaches require a specific functional group on the substrate and the receptor before the covalent immobilization of the PDA liposomes to the substrate and the tethering of the receptors to the PDA layer, respectively.…”