Radioimmunoassay | Radiolabelled antigen and radioactive measurement | Accurate and sensitive; reliable and applicable; easy operation;absolute quantification | Health hazards; radioactive contamination;limited stability | [15-16] |
ELISA | Enzyme-labeled antigens or antibodies, enzyme-mediated visible color change or fluorescence to quantitative and qualitative measurements | Simplicity and scalability; ease operation; automated high-throughput; visual inspection; detection of a molecule at a low concentration | Time-consuming; high cost;moderate sensitivity;relatively complex strategy;specific equipment | [17-18] |
Chemiluminescence immunoassay | Chemiluminescent substance labeled antigen or antibody,luminescence signal detection | High sensitivity and specificity;wide linear range; rapid and simple analysis; no scattered light interference | Weak signals and short luminescence time; limited precision for small molecules; matrix interference in complex samples | [19-20] |
PCR | Enzymatic synthesis and amplification of specific DNA fragment; product analyze | High sensitivity; small amount of sample; multiplex; precise and accurate target quantification | Expensive with poor integration and multiplexing capability | [21-22] |
Next-generation sequencing | Sequence millions of DNA molecule in one single run | Fast and efficient; high throughput; suitable for individual therapy of cancer | Expensive and mass processing of data; multiple steps of sample preparation; prone to mistakes | [23-24] |
Mass spectrometry | Ionizing chemical species, separating and analyzing based on their mass-to-charge ratio | Rapid and sensitivity; high-throughput; structure identification; able to find new tumor biomarkers | Expensive equipment and complicated operation;invasive; low abundant proteins detection; prone to interference | [25-26] |
SPR | Refractive index changes occurring from the capture of a molecule on the plasmonic surface | Label-free and real-time; high sensitivity and accuracy; suitable for a broad range of biofluids | Interference from complex samples; affects specificity and detection limits; most of them are in the proof-of-concept level | [27-29] |
SERS | Difference in Raman scattering spectra of different molecule | Multiplexing capacity; high sensitivity and specificity; non-destructive and non-invasive | Expensive and expert-dependent equipment; batch to batch reproducibility of SERS substrates | [30-31] |
Electrochemical sensors | Converts an interaction signal between a biometric element and a recognition target into a detectable electrical signal | High sensitivity; rapid and low cost; simple and suitable for microfabrication; mass production and integration | Lack of specificity for the captured cancer cells; lack the ability to detect intracellular protein markers | [32-33] |
Flow cytometry | Measurement of cell size and cell granularity, expression of cell surface and intracellular molecules | Sorting capability; high-throughput measurement;rapidly counts | Indirect and in vitro measurement; time-consuming preparation | [34] |
Fluorescence | Change of fluorescence spectrum and fluorescence intensity | High sensitivity and stability;simplicity and rapidity; biocompatibility; accurate data collection | Spectral overlap; background fluorescence; photobleaching; non-specific binding labeling | [35,31] |