Response to Comment on 'Preparation of Superparamagnetic Ribonuclease A Surface-Imprinted Submicrometer Particles for Protein Recognition in Aqueous Media'

摘要

The comment by Fu et al. pointed out that the specific template protein binding capacity of the imprinted particles reported in our papers is over 10 or even 100 times higher than the theoretical limit. Therefore, they questioned the reason for the imprinting effect of such high loadings. In giving a possible explanation to this discrepancy, they also doubted whether the nonimprinted materials had been washed with the sodium dodecyl sulfate/acetic acid (SDS/Aa) solution in the similar manner as the imprinted counterparts during the template removal process of our work, as they have found that the template-removing solution could impose an additional protein-binding capacity on the imprinted particles, thus causing them to adsorb "more-than-expected" template protein molecules and giving a false imprinting effect. We acknowledge such concerns and wish to clarify these points. First, although this had been clearly indicated in our papers, we would like to further reassure that all of the control nonimprinted polymers had been fabricated following the exact same methodology as that of their counterpart imprinted particles, except without the addition of the template protein molecules. This included the postprocessing and treatment of the particles. Although the nonimprinted polymers had been prepared in the absence of template molecules, they were similarly washed and treated using the SDS/Aa solution so as to ensure a fair comparison between them and the imprinted polymers in the subsequent protein batch rebinding tests. The subsequent washing with DI water was also monitored using a UV-visible spectrophotometer for the SDS content in the supernatant after each cycle until the spectra obtained were similar to that of pure DI water. In addition, an X-ray photoelectron spectroscopy (XPS) surface analysis conducted on both the molecularly imprinted polymers (MIP) and corresponding nonimprinted polymers (NIP) nanoparticles after the final cycle of washing showed a nondetectable sulfur composition, thus it can be concluded that all of the SDS had been removed. This observation would eliminate the possibility of false imprinting as suggested by Fu et al.