The color of emitted light of Quantum dots used in fluorescence microscopy depend on:
The color of emitted light of Quantum dots used in fluorescence microscopy depend on:
Select an option to attempt
Correct Answer: Option B
Explanation
Quantum dot emission and particle size:Quantum dots (semiconductor nanocrystals, e.g., CdSe/ZnS) exploit quantum confinement:• As particle size DECREASES, the band gap INCREASES (quantum confinement effect).• Larger band gap → higher energy photons emitted → BLUE/shorter wavelength emission.• Smaller band gap (larger QD) → lower energy photons → RED/longer wavelength emission.Practical range:• ~2 nm QD → blue emission (~450 nm)• ~5 nm QD → green emission (~530 nm)• ~7 nm QD → red/orange emission (~620 nm)The emission wavelength is determined by PARTICLE SIZE (not chemical composition alone).Answer: Quantum dot emission wavelength is determined by its size; larger dots emit at longer (red) wavelengths.