Structural effects and nanoparticle size are essential for quantum dots–metallothionein complex formation

•MSA-capped CdTe QDs and MT do not create firmly bound stabile complex.•Electrostatic interactions are responsible for interaction of MT with MSA-CdTe QDs.•QDs size had a strong influence on interaction between QDs and MT.•The smallest QDs had the highest affinity to MT.

Interaction between semiconductor nanocrystals, cadmium telluride quantum dots (CdTe QDs) capped with mercaptosuccinic acid (MSA) and metallothionein (MT) was investigated. MSA-capped CdTe QDs were synthesized in aqueous solution. Mixture of MT and MSA-capped CdTe QDs has been investigated by various analytical methods as follows: tris-tricine gel electrophoresis, fluorescence evaluation and electrochemical detection of catalysed hydrogen evolution. The obtained results demonstrate that MSA-capped CdTe QDs and MT do not create firmly bound stabile complex. However, weak electrostatic interactions contribute to the interaction of MT with MSA-capped CdTeQDs. It can be concluded that QDs size influences the QDs and MT interaction. The smallest QDs had the highest affinity to MT and vice versa.

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