Polymer- and colloid-mediated bioassays, sensors and diagnostics

Hydrogel Based Biosensors for In Vitro Diagnostics of Biochemicals, Proteins, and Genes

“…Besides the stimuli‐responsive hydrogels, there are new emerging detection platforms employing the biomimetic characteristics of hydrogels. Among biomimetic features, a highly swollen 3D network structure resembles the native tissue condition that supports more robust interactions among biomolecules and their receptors . This is particularly beneficial for the detection of proteins and genes due to their complex structures and low diffusion profiles in an aqueous medium.…”

“…Therefore, the hydrogel can provide an ideal environment for biomolecules to be retained within the system, while maintaining their biological activities. It is known that many of conventional biosensors suffer from low activity issues due to the limitations of two‐dimentional (2D) solid substrates . Non‐specific adsorption and denaturation of analytes often occur, which reduces the biological activities of target analytes when encountering interacting ligands.…”

“…The main drawbacks of these systems are likely to be slow response rates and lack of signal amplification. Besides the physical changes of the hydrogel, various novel approaches have recently reported employing the 3D‐network structures of the hydrogel for enhancing the sensitivity and selectivity . As compared to the conventional lab‐based analysis (gas chromatography, immunoassay, and PCR), hydrogel‐based biosensors can offer much broader use in various diagnostics.…”

Enhancing Single Molecule Imaging in Optofluidics and Microfluidics

“…As discussed in the introduction, these attachment points need to exhibit certain properties in order to enhance the imaging of single molecules. In addition to their capacity to attract the ‘signal molecules’ with high affinity and resist non-specific adsorption of molecules that can contribute to noise [125–128], there are additional properties that we summarize below: Simplicity and minimal preparation requirements: Single molecule imaging and detection is becoming a substantially interdisciplinary field, comprised of biologists, physicists and chemists. Hence, synergetic also to microfluidics, the chemical modification needs to be simple and require few implementation steps;…”

“…The technique involved the polymerization of acrylamide in glass capillaries and exhibited significant prevention against non-specific recognition, high sensitivity in isolated nucleic acid imaging, as well as stability over repeated polymerase chain reactions (PCR) [128]. With regards to single molecule DNA sequencing, another technique is based on the use of polyelectrolyte films (Figure 5b).…”