Instrument-free visual quantitative detection in the chemical and biochemical analysis is of great significance in practical applications especially in point-of-care testings and in places where resources are limited; however, its development has been relatively slow. By far, the well-developed, instrument-free visual quantitative detection is mainly scale-ruler-and time-based and is primarily used in microfluidic technology. This thesis aims to realize time-based instrument-free visual quantitative detection in chemical and biochemical analysis by employing a clock reaction, a type of chemical reaction displaying characteristic clocking behavior. The goal is to use a clock reaction to achieve instrument-free visual quantitative detection of more chemical and biochemical analytes and to...[ Read more ]

Instrument-free visual quantitative detection in the chemical and biochemical analysis is of great significance in practical applications especially in point-of-care testings and in places where resources are limited; however, its development has been relatively slow. By far, the well-developed, instrument-free visual quantitative detection is mainly scale-ruler-and time-based and is primarily used in microfluidic technology. This thesis aims to realize time-based instrument-free visual quantitative detection in chemical and biochemical analysis by employing a clock reaction, a type of chemical reaction displaying characteristic clocking behavior. The goal is to use a clock reaction to achieve instrument-free visual quantitative detection of more chemical and biochemical analytes and to gain a better understanding of the mechanism of the method in detail.

The first major contribution of the thesis is to use the clock reaction to quantitatively distinguish between different aggregation levels of gold nanoparticles (AuNPs), and then to combine the clock reaction and the aggregation of AuNPs into the instrument-free visual qualitative detection method. As a result, the scope of instrument-free visual quantitative detection can be greatly expanded.

The second major contribution of the thesis is the combination of a clock reaction with a gold nanoparticle–linked immunosorbent assay (GNLISA) to achieve instrument-free visual quantitative detection in bioanalysis. The feasibility of the method is demonstrated by the detection of prostate-specific antigen (PSA). This method does not require the use of the reporting enzyme in traditional ELISA and is, therefore, more stable than the latter. This enables a much wider application of the instrument-free visual quantitative detection in chemical and biochemical analysis.

The third contribution of the thesis is the implementation of the as-developed method in the instrument-free visual quantitative detection of thrombin, thereby further expanding the scope of our method.

Last but not the least, this thesis provides our current understanding of the mechanism of the clock reaction employed in instrument-free visual quantitative detection for the first time.