Question

a)List four advantages of optical bioimaging over conventional MRI and CT.

b) Quantum dots are high-efficiency fluorophores, but it will not work if simply injecting quantum dots into an animal for fluorescence imaging; quantum dots need to be conjugated with some functional groups like antibody. Briefly explain why.

Answer 1

Q (a) Advantages of optical bio-imaging over conventional MRI and CT.

(1) Optical Bio imaging has High spatial resolution
(2) It has Real time imaging with low acquisition time ie. it takes lower time.
(3) Due to its high resolution it is Highly sensitive.
(4) Because Bio-imaging is inexpensive hence it is affordable.
(5) It usually uses Visible or near-infrared light

CT scan has a disadvantage of Radiation exposure Poor soft tissue contrast
MRI has disadvantage of Expensive Long acquisition time and limited sensitivity

Q (b)To improve in vitro and in vivo imaging quality and detection sensitivity in biological fields,
multiplex capabilities QDs have been developed.Quantum dots (QDs) are a group of semiconducting
nano-materials with unique optical and electronic properties. They have distinct advantages over
traditional fluorescent organic dyes in chemical and biological studies in terms of tunable
emission spectra, signal brightness, photo-stability, and so forth.Quantum Dots (QD) cannot
directly bind to the bio-molecure or tissues.The main phenomena of binding od QDs is by electrostatic attraction.
To bind the QDs to any tisssue. it is conjugated with some polar bio-molecules(Antibody) that contain groups like
COOH-/NH2,N3,HS etc
After conjugating the antibody with QDs , the QDs are placed into the respective location for fluorescence.