## 1 Introduction  
Inspired by the mechanism of enzyme catalysis and antibody formation, researchers have been committed to exploring similar synthetic approaches with the purpose of obtaining tailored binding materials by chemical means [1]. To date, molecular imprinting has proven to be the most efficient and versatile technique for incorporating specific molecular recognition sites into polymers leading to polymeric artificial receptors [2; 3; 4; 5; 6; 7; 8]. The essential molecular imprinting process involves the self-assembly of a template molecule and a functional monomer via either non-covalent interactions (such as hydrogen bonding, van der Waals forces, ionic interactions, hydrophobic interactions or metal coordination interactions, _etc._) or via reversible covalent bonds, the resulting complexes subsequently being copolymerized with a suitable cross-linker [9]. After removal of the templates from the obtained cross-linked polymer network, binding cavities complementary in shape, size and functionality to the template are formed [10] (Figure 1). The resultant molecularly imprinted polymers (MIPs) have found use in a wide range of applications encompassing the fields of separation processes (chromotography, capillary electrophoresis, solid phase extraction, and membrane separation), immunoassay [11], antibody mimics [12], artificial enzymes [13], sensors [14], catalysis [15], organic synthesis, drug delivery [16] and drug development [17]. This versatility stems from their favorable properties, e.g., mechanical, thermal, chemical stability, ease of preparation, low cost, and especially high affinity. In spite of the tremendous progress that has been made in the molecular imprinting field, many challenges (e.g., applications in biology) remain to be addressed, especially in the design of advanced  
Figure 1: Highly schematic representation of the molecular imprinting process. Reprinted with permission from Reference 3. Copyright 2014, Wiley. MIP materials mimicking the biological receptors [18, 19]. It is known that one of the most fascinating characteristics of the natural receptors is their high responsiveness towards external stimuli (e.g., the temperature, pH, _etc._). Therefore, in order to find the perfect consistency between the synthetic receptor and the natural one, stimuli-responsive (also called \"stimuli-sensitive\" or \"smart\") MIPs have attracted considerable research interest in recent years [20, 21, 22, 23]. The effective and general methodology to design stimuli-responsive MIPs is the combination of stimuli-responsive materials and the molecular imprinting technique, which endow the MIPs with the ability to respond to external stimuli while modulating their affinity for the target molecules and providing a switchable capacity of the binding or releasing processes. Currently, a variety of intelligent MIPs have been prepared which respond to specific stimuli such as changes in temperature [24], pH [25], incident light [26], ionic strength [27], or even the presence of a specific molecule [6, 28]. [PERSON] _et al._ have reviewed work in the field until 2008 with special focus on a series of stimuli-responsive MIPs and their applications in drug delivery systems (DDS) [29]. The article gave a systematic classification of stimuli-responsive MIPs in DDS. Moreover, the development of stimuli-responsive MIPs, such as their applications and methodologies, has grown rapidly in recent years [6, 30, 31, 32]. Therefore, in this review, we provide an overview of different responsive MIPs developed until now (Table 1), especially their synthetic methods, material formats and applications, furthermore, considering the challenges presently encountered and some feasible resolutions. By means of the points raised in this article, we would like to provide some assistance for further development of preparation methodologies and the expansion of some potential applications in the field of stimuli-responsive MIPs.