Quantum Dots and Their Applications in Biotechnology
Invisible tattoos, LEDs and lasers. Some of the many uses regarding Dr Matt Booth’s seminar on Quantum Dots and their applications in biotechnology. He presented a very intriguing class, and we’ll go through some of the details and key point brought up.
Quantum dots are incredibly tiny crystals made from semiconductors, so small that they behave differently from normal materials. As Matt explains “Quantum dots are nanocrystals of semiconducting material with dimensions smaller than the exciton radius, meaning the electronic states are discrete, much like artificial atoms”. That ‘discrete’ behaviour is what gives quantum dots their magic, causing them to glow with different colours depending on their size. This is because a smaller quantum dot provokes a larger band gap and this size dependence effects the colour of emitted light.
These dots are very useful in biotechnology as an organic dye replacement, or should I say upgrade. As Matt puts it “Compared with organic dyes, quantum dots are much more photostable; they can undergo many excitation and emission cycles without significant degradation.”. This allows us to perform much longer and complex experiments with them at the atomic level.
These advantages were first demonstrated in a landmark 1998 paper where quantum dots were used to label biological molecules [1]. This work showed that quantum dots could bind to proteins and light up cells far better than traditional dyes. Since then, their use has exploded. A major review in science described how quantum dots are now used in live-cell imaging, disease diagnostics, and even inside animals [2]. Researchers can attach antibodies to quantum dots, so they bind only to specific cells, such as cancer cells: “Surface functionalization of quantum dots enables attachment of targeting molecules, such as antibodies, to selectively bind to disease markers in biological systems.”
However, their use comes with caution. Matt describes nanotoxicity as a complex issue with using quantum dots as they may have unexpected or unpredicted reactions with biological systems. This is an active area of research, discussed in detail by Smith and Nie, who explain how chemists try to make quantum dots safer and more biocompatible [3].
As a whole, this seminar topic was very interesting to delve into. A captivating area of research that introduces the audience to a whole new world of quantum biotechnology.
References:
[1] Bruchez et al., 1998, Semiconductor nanocrystals as fluorescent biological labels
[2] Michalet et al., 2005, Quantum dots for live cells, in vivo imaging, and diagnostics
[3] Smith & Nie, 2010, Semiconductor Nanocrystals: Structure, Properties, and Band Gap Engineering
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Very descriptive with good referencing and understanding. I would consider a different structure to the piece to make it more cohesive,