A blood glucose meter (component measurement apparatus) includes a measurement chip, and an apparatus main body including an insertion hole. The measurement chip includes a pair of plate pieces, a spacer arranged between the pair of plate pieces, and a cavity that can retain blood. A pair of wall portions of the insertion hole, facing each other at a measurement unit and in the vicinity of the measurement unit, is separated from each other with a width smaller than a thickness of the measurement chip in a lamination direction. The spacer elastically deforms by a state in which the pair of plate pieces is pressed by the pair of wall portions and defines a width of the cavity.

A system and method for collecting, transporting, and analyzing dried bodily fluid samples using a sample collection device incorporating extraction markers, an imaging device to take images of dried samples on the collection device, and a computing device to analyze data points from the images so as to measure various properties of the collected sample such as the volume of blood initially collected, and the portion of that volume containing plasma and erythrocytes.

Described here is a test strip for detection of melamine, comprising: a support configured for capillary flow of a fluid sample from a first end of the support to a second end of the support that is downstream from the first end; a conjugation pad disposed adjacent to the first end of the support and including nanoparticles configured for suspension in the sample flowing past the conjugation pad, the nanoparticles configured to produce a colorimetric effect when exposed to melamine; and a test portion downstream of the conjugation pad and including a molecular recognition agent immobilized on the support and having an affinity for melamine.

Paper microfluidic devices for the detection of bodily fluids are provided. Such devices can be used, for example, for detection of bodily fluids from or at crime scenes, including blood, saliva, semen, urine, feces, vaginal fluids, and perspiration. Detection can be performed using colorimetric reagents that react when placed in contact with the fluid of interest. A single device can be used to test for multiple bodily fluids at the same time.

Devices to detect analytes (e.g., charged species such as ions) in samples are provided as are methods for their use. The devices comprise a tube or container comprising a water-immiscible sensing oil phase comprising at least one sensing chemical that binds the at least one analyte. The tube further receives an aqueous sample. Upon mixing of the two immiscible phases, the analyte partitions into the oil phase and binds to the sensing chemical, delectably changing the optical properties of the sensing chemical (or of an associated reporter molecule). Detection of the changes permits quantification of the amount or concentration of analyte in the sample without optical interference from the sample. The devices are suitable for home use and other decentralized settings.

Described herein, in some embodiments, are kits, devices and sensors comprising a conjugated aldehyde. In some embodiments, the sensors comprise an ,-unsaturated aldehyde. Also described herein are methods of analyzing stress in a plant sample, the methods comprising: contacting the plant sample with a sensor or a device comprising the sensor; and comparing color intensity of the sensor or the device with a reference color intensity to determine stress level of the plant.