摘要： In this chapter, the structure, characteristics, and synthesis processes of QDs were summarized. The most common electrochemical methods for QDs were also represented by reviewing their potential applications in biosensor technology. Many specific applications have been realized by utilizing the unique characteristics of QDs. However, their limited commercial availability; requirements of demanding synthesis procedures, analysis of multicomponent complex samples, and in situ analysis; and lack of validation with real samples are other disadvantage of QDs. The design of QD-based biosensors is also complicated due to limitedly defined redox behavior of nanocrystals resulting in difficulty with probing their redox levels. Therefore, extensive investigations are needed on the redox properties of QDs, despite having a large amount of literature on their synthesis, properties, and applications. The interactions between the system parameters can be clarified by using the mathematical models. To solve the model equations analytically, it is introduced to equivalent systems having identical spectra and wave functions, and these forms have to satisfy the solvability conditions. 3D QDs can be modeled by an ODE accurately, when the dimension of the cross section is very small and the energy levels are low. To obtain high accuracy of the effective mass approximation model, sizes of the QDs should be 10–20 nm. Optimum design problems for QD systems generally have discrete search spaces and involve highly nonlinear terms. Therefore, the selection of any traditional optimization methods to solve optimization problems is not appropriate. In these circumstances, it is useful to perform modern optimization algorithms such as the GA, DE, and SA methods. By incorporating mathematical models and optimization approximations to QD-based bioloelectrochemical systems, their performances will excel far beyond the current state in the near future.