A Wearable Microfluidic Chip For Cortisol Detection

Cortisol is a"stress biomarker"of stress-related disorders,providing real-time information about human health.Thesis studies wearable devices based on microfluidic chips,which are smart devices that integrate collection,transportation,and detection,allowing individuals to monitor their own mental health in real time;providing warnings to people with poor mental health assessments and urging them to change badly The way of life and work to relieve physical and mental stress;for people with poor mental health assessment,guide them to seek medical treatment as soon as possible to avoid the deterioration of the condition caused by delay in seeking medical treatment;it is convenient for people who are undergoing mental health diagnosis and treatment to monitor their own psychological pressure,and provide doctors with a It is an auxiliary diagnostic method and is expected to become one of the main diagnosis and treatment methods.In the era of well-off for the whole people,the health of the whole people is also getting more and more attention.If we can build a set of personal flexible wearable devices that are easy to mass-produce,portable and low-power consumption,we can better achieve national health.First,a nanoelectrochemical biosensor based on black phosphorus-nano-gold(BP-Au)material was designed to detect the concentration of cortisol.The black phosphorus-nano-gold composite material was used to improve the electrical signal of the electrochemical reaction.Cortisol concentration is detected by the difference in electrical signals caused by different concentrations of cortisol samples.The key design parameters of the electrochemical biosensor are as follows:aptamer fixation time,aptamer concentration,and incubation time for cortisol and aptamer binding.These parameters can be adjusted to obtain the best assay dynamic range and detection limit(LOD).Further,we developed a smartphone-based portable 3D microfluidic origami nanobiosensor to detect cortisol levels in sweat.Biosensing using molybdenum disulfide(Mo S₂)nanosheet-mediated fluorescence resonance energy transfer(FRET)and fluorescently labeled aptamers.In order to realize the collection,transportation and detection of small volume of human sweat,a three-dimensional origami microfluidic chip with multi-layer structure was designed.Use a 3D-printed customized mobile phone to detect the black box to collect the fluorescent signal,and then transmit it to the computer for analysis and calculation using fluorescence analysis software to obtain the concentration of cortisol.Key design parameters for microfluidic origami biosensors include characterization of various paper substrates,concentration and incubation of Mo S₂ nanosheets,and reaction time,which are tuned for optimal assay dynamic range and limit of detection(LOD).Portable biosensors provide a fast,low-cost,convenient and non-invasive sensing solution for instant analysis of cortisol levels in sweat.