The invention relates to compounds of structural formula and structural formula :or a pharmaceutically acceptable salt, solvate, clathrate, or prodrug thereof, wherein R, R1, R2, Z, L, and n are defined herein. The beginning of each feed gap is provided with a grinding section, which is followed in the apparatus by a mixing section. 83 and a characteristic time value of less than 257 milliseconds. The disclosed device and methods of use enjoy substantial benefits over the prior art, including simplicity of use by an operator, rapid in situ determinations of one or more analytes, and single-use methodology that minimizes the risk of contamination of both operator and patient. When the movable contact is in operation, the movable contact touches the object at an outer section of the flat face and along the circumferential direction. Luminescent devices incorporating the composite materials are also disclosed.