Surface-enhanced fluorescence from porous, metallic sculptured thin films ͑STFs͒ was demonstrated for sensing of bacteria in water. Enhancement factors larger than 15 were observed using STFs made of silver, aluminum, gold, and copper with respect to their dense film counterparts. The STFs used are assemblies of tilted, shaped, parallel nanowires prepared with several variants of the oblique-angle-deposition technique. Comparison between the different films indicates that the enhancement factor is higher when the tilt is either small ͑Ͻ30 deg͒ or large ͑Ͼ80 deg͒; thus, the enhancement is higher when only a single resonance in the nanowires is excited.

Cyclic peptides are important natural products and hold great promise for the identification of new bioactive molecules. The split‐intein‐mediated SICLOPPS technology provides a generic access to fully genetically encoded head‐to‐tail cyclized peptides and large libraries thereof (SICLOPPS=split‐intein circular ligation of peptides and proteins). However, owing to the spontaneous protein splicing reaction, product formation occurs inside cells, making peptide isolation inconvenient and precluding traditional in vitro assays for inhibitor discovery. The design of a genetically encoded, light‐dependent intein using the photocaged tyrosine derivative ortho‐nitrobenzyltyrosine incorporated at an internal, non‐catalytic position is now reported. Stable intein precursors were purified from the E. coli expression host and subsequently subjected to light activation in vitro for both the regular protein splicing format and cyclic peptide production, including the natural product segetalin H as an example. The activity of the intein could also be triggered in living cells.

The use of various whole-cell organisms as tools for monitoring water contaminants is reviewed and evaluated. Their suitability and value for assessing a range of environmental problems from the impact of pollution, homeland defense issues, conservation, and the long-term degradation and recovery of ecosystems is discussed. Guidelines are provided for the choice of appropriate bioreporter organisms, transducers, and immobilization methods. Examples of the use of a broad spectrum of whole-cell bioreporters in assessing a variety of environmental problems are summarized.