Rapid identification of bacteria with a disposable colorimetric sensing array.

Rapid identification of both species and even specific strains of human pathogenic bacteria grown on standard agar has been achieved from the volatiles they produce using a disposable colorimetric sensor array in a Petri dish imaged with an inexpensive scanner. All 10 strains of bacteria tested, including Enterococcus faecalis and Staphylococcus aureus and their antibiotic-resistant forms, were identified with 98.8% accuracy within 10 h, a clinically important time frame.

Colorimetric sensor arrays for volatile organic compounds.

The development of a low-cost, sensitive colorimetric sensor array for the detection and identification of volatile organic compounds (VOCs) is reported. Using an array composed of chemoresponsive dyes, enormous discriminatory power is possible in a simple device that can be imaged easily with an ordinary flatbed scanner. Excellent differentiation of closely related organic compounds can be achieved, and a library of 100 VOCs is presented.

Novel lactonization with phenonium ion participation induced by hypervalent iodine reagents.

[reaction: see text] A novel lactonization of 4-aryl-4-pentenoic acids is described using aryl-lambda(3)-iodanes as reagents for this transformation. The hypervalent iodine species acts as a hypernucleofuge, generating intermediate phenonium ions, which react to aryl-migrated lactones.