The recent developments on iron-based adsorbents such as iron oxyhydroxides nanoparticles, zero-valent iron, bimetallic oxides, and iron oxyhydroxide-doped composite materials are fully discussed in this review.

Metastasis, the capability of tumor cells to spread and grow at distant sites, is the primary factor in cancer mortality. Because metastasis in sentinel lymph nodes suggests the original spread of tumors from a primary site, the detection of lymph node involvement with cancer serves as an important prognostic and treatment parameter. Here we have developed a panel of DNA aptamers specifically binding to colon cancer cell SW620 derived from metastatic site lymph node, with high affinity after 14 rounds of selection by the cell-SELEX (systematic evolution of ligands by exponential enrichment) method. The binding affinities of selected aptamers were evaluated by flow cytometry. Aptamer XL-33 with the best binding affinity (0.7 nM) and its truncated sequence XL-33-1 with 45 nt showed excellent selectivity for recognizing target cell SW620. The binding entity of the selected aptamer has been preliminarily determined as a membrane protein on the cell surface. Tissue imaging results showed that XL-33-1 was highly specific to the metastatic tumor tissue or lymph node tissue with corresponding cancer metastasis and displayed an 81.7% detection rate against colon cancer tissue with metastasis in regional lymph nodes. These results suggest that XL-33-1 has great potential to become a molecular imaging agent for early detection of lymph node tissue with colon cancer metastasis. More importantly, this study clearly demonstrates that DNA ligands selectively recognizing metastatic cancer cells can be readily generated by metastatic-cell-based SELEX for potential applications in metastatic cancer diagnosis and treatment.

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The development of a highly active TiO 2 photocatalyst for energy and environmental use is a great challenge. In this work, we report that the addition of sodium borate to an aqueous suspension of anatase TiO 2 at neutral pH can result in a significant enhancement in the rate of phenol degradation. Similar results were also observed from 2,4-dichlorophenol degradation, spin-trapped OH radical formation, H 2 O 2 decomposition, and chromate reduction in the presence of phenol. This borate-induced rate increase for phenol degradation was determined not only by the amount of borate adsorption but also by the structure of borate species (pH effect). A (photo)electrochemical measurement with the TiO 2 film revealed that upon addition of borate, the hole consumption by phenol and the electron consumption by O 2 were accelerated and decelerated, respectively. Moreover, the flat band potential of TiO 2 was negatively shifted by 81 mV. Since the hole oxidation of water to O 2 remained unchanged, it is proposed that a borate radical is produced, followed by regeneration through phenol oxidation. This borate-mediated hole transfer would promote the electron transfer to O 2 and consequently improve the efficiency of the charge separation for phenol degradation at interfaces.