Concentration determination method

A concentration determination method, comprising:

• diluting a sample fluid having a target material therein with a 1st dilution factor to an Nth dilution factor to respectively form a 1st sample to an Nth sample, wherein the Nth dilution factor is greater than the Nth-1 dilution factor;
• providing a 1st bio-sensing integrated circuit to an Nth bio-sensing integrated circuit, wherein the 1st bio-sensing integrated circuit to the Nth bio-sensing integrated circuit respectively comprise a 1st sensory array to an Nth sensory array;
• respectively applying the 1st sample to the Nth sample onto the 1st bio-sensing integrated circuit to the Nth bio-sensing integrated circuit;
• performing a bio-sensing process on the 1st sample to the Nth sample by the 1st sensory array to the Nth sensory array of the 1st bio-sensing integrated circuit to the Nth bio-sensing integrated circuit during a time period between a first time t1 and a second time t2 to obtain a 1st measurement value to an Nth measurement value at the second time t2 respectively for the 1st sample to the Nth sample;
• converting the 1st measurement value to the Nth measurement value to digital signals through a Trans-impedance Amplifier (TIA) and an analog-to-digital converter (ADC);
• comparing the digital signals with a threshold value and evaluating which one of the digital signals is below the threshold value, by a microcontroller unit (MCU), to determine a threshold dilution factor, wherein the threshold dilution factor corresponds to a largest dilution factor that has a measurement value higher than the threshold value, wherein the threshold value ranges from about 0.1 μA to about 10 μA;
• and
• calculating a concentration of the target material in the sample fluid based on the threshold dilution factor and limit of detections of the 1st bio-sensing integrated circuit to the Nth bio-sensing integrated circuit.

A concentration determination method, comprising:

• providing a 1st sample to an Nth sample respectively having a concentration of 1/N1 to 1/Nth of a sample fluid, wherein the concentration decreases from the 1st sample to the Nth sample;
• respectively applying the 1st sample to the Nth sample onto a 1st assay to an Nth assay;
• performing a bio-sensing process on the 1st sample to the Nth sample by a bio-sensing integrated circuit having the 1st assay to the Nth assay during a time period between a first time t1 and a second time t2 to obtain a 1st measurement value to an Nth measurement value at the second time t2 respectively for the 1st sample to the Nth sample;
• converting the 1st measurement value to the Nth measurement value to digital signals through a Trans-impedance Amplifier (TIA) and an analog-to-digital converter (ADC);
• comparing the digital signals with a threshold current and evaluating which one of the digital signals is below the threshold current, by a microcontroller unit (MCU), to determine a threshold dilution factor, wherein the threshold dilution factor corresponds to a largest dilution factor that has a measurement value higher than the threshold current, wherein the threshold current ranges from about 0.1 μA to about 10 μA;
• and
• calculating a concentration of the target material in the sample fluid based on the threshold dilution factor and a limit of detection of the bio-sensing integrated circuit.