A piece of 1-mm thickness optical glass was mounted at the bottom of the reservoir; photons produced during the Ru[(bpy).sub.3.sup.2+] ECL reaction passed through the glass window and were detected by a
photomultiplier tube.
The elements constituting the reader used in the chemiluminescent assays were as follows: two lasers for reaction mixture illumination; an illumination chamber; optical train with collimating lenses, filter wheel, and shutter;
photomultiplier tube (PMT); controlling computer; and software.
The BlankCell procedure serves to calibrate the chemiluminescence signal received by the
photomultiplier tube to a solution of known concentration.
The heart of the unit is a
photomultiplier tube descended from the light-sensitive devices pioneered by Jakob Kunz and Joel Stebbins early in this century (S&T: May 1992, page 496).
The light drives the photoelectric effect in a
photomultiplier tube that produces a measurable pulse proportional to the energy of the incident gamma-ray photon.
Using readings from a sensitive light detector called a
photomultiplier tube, they offer the first evidence of a biological version of the phenomenon known as sonoluminescence.
31 Physical Review Letters, the duo described using a sensitive
photomultiplier tube and lenses to collect light from a metal sample as it was scanned with the STM tip.