||Bioimaging techniques are not only important in clinical diagnosis but in research. As many bioimaging techniques are developed, fluorescence technique is one of the important bioimaging methods that is really useful in clinical diagnosis and research due to its good spatial resolution and time resolution. Semiconducting polymer dots (pdots) has the potential for bioimaging fluorescence probe because of its good quantum yield, high phtostability, suitable size for bioconjugation, low biotoxicity and tunable emission wavelengths. Pdots has drawn many scientist’s attentions due to its advantages and really suitable for in vitro/vivo bioimaging research.|
Reacently different wavelength pdots have been developed including near infrared emmition pdots. This is significant for bioimaging because near infrared has more penetration distance which can travel longer in the tissue and it can eliminate the autofluorescence of biomolecule in human body to reduce the noise. The most important of near infrared fluorescence probe, it is revatively lower energy than other wavelength fluorescence probe. However, the challenging part of developing NIR pdots is most NIR dyes with many π conjugated structures and benzenes tend to have π-π stacking in aggregation form that lead to ACQ effect (aggregation caused quenching) which cuase NIR dyes’ low quantum yield. Moreover, our lab has develop some NIR emission pdots, unfortunately the emission band was relatively broad (80-150 nm), and still challenging for multicolor bioimaging due to the emission section
Therefore, my first section of this paper is that molecular engineering and design of semiconducting polymers to develop polymer dots as fluorescent probe with narrow-band, near- infrared emission for in vivo biological imaging. By using synthetic method, we develop polymer with donor-bridge-acceptor structure that the donor prvide basic steric hindrance and absorption of light for pdot; there are four bridges we used that have increasing bulky structure and they provide bulky side chain for pdots to prevent from ACQ effect; finally, we select two near-infrared dyes with narrow-band emission: pthalocyanine (Pc) and boron-dipyrromethene (BODIPY) as our acceptor. In this section, we optimized all combination of the donor、bridges、acceptors and come up with the best enrgy transfer ration of each polymer. Then we chose the best performance of the pdots for further experiment such as cell labeling、zebra fish bioimaging and
mice tumor tracking.
Second section of this paper is design of PFO pdots with boronic acid based anthracene dyes for glucose sensing. Glucose concentration in human blood is really important in clinical diagnosis and daily follow-up for patients with cardiovascular disease. Therefore, the second section of this paper we combined PFO pdots that has 550 nm fluorescence and boronic acid based anthracene dye (AAS) that is a dye will turn on when chelate with glucoe and emits green fluorescence. The mechanism in this project is using the PFO pdots with good quantum yield to enhance the fluorescence of the AAS when it detected glucose through FRET mechanism in order to increase
the sensitibity of the detection of glucose.
Ultimately, we want to develop pdots with AAS glucose sensor conbine with test paper in order to achieve point-of-care test. By using this test paper, people in home can easily use this paper to determine the blood sugar level and follow up the daily
detection for clinical diagnosis.