Biochips play a crucial role in biological research fields such as systems biology and disease biology, and their clinical applications are constantly increasing. It is a set of microarrays placed on a solid surface of the substrate to perform thousands of reactions in a shorter time. The development of biochips mainly involves the combination of molecular biology, biochemistry, and genetics. Biochips are used to analyze organic molecules related to living organisms. This article discusses what biochips are, their types, uses, disadvantages, and applications.

　 　What are biochips?

　　Biochips are a set of small microarrays placed on a solid substrate that allows many experiments to be performed simultaneously, thus achieving high throughput in a shorter time. The device contains millions of sensor elements or biosensors. Unlike microchips, they are not electronic devices. Each biochip can be considered a microreactor that can detect specific analytes such as enzymes, proteins, DNA, biomolecules, or antibodies. The main function of the chip is to perform hundreds of biological reactions in seconds, such as decoding genes (DNA sequences).

　　 Working principle of biochips:

　　The working principle of biochips mainly includes the following steps:

　　Step 1: The operator generates a low-power electromagnetic field through radio signals

　　Step 2: The fixed biochip starts

　　Step 3: The activated chip transmits the identification code back to the operator via radio signals

　　Step 4: The reader strengthens the received code, converts it into a digital form, and finally displays it on the LCD.

　　 Components of biochips

　　Biochips consist of two parts: a transponder and a reader.

　 　1) Transponder

　　There are two types of transponders: active transponders and passive transponders. A passive transponder means it does not contain any of its own energy or battery, while a passive transponder means it is not active until the operator activates it by injecting a low charge into it. The transponder consists of four parts, such as an antenna coil, a computer microchip, a glass capsule, and a tuning capacitor.

　　The computer microchip stores identification (UID) numbers ranging from 10 to 15 bits in length.

　　The antenna coil is very small and primitive, and this type of antenna is used to send and receive signals from a scanner or reader.

　　The tuning capacitor can be charged by a small signal (i.e., 1/1000 watt) sent by the operator.

　　The glass capsule contains the antenna coil, capacitor, and microchip, and is made of a biocompatible material, namely soda-lime glass.

　 　2) Reader

　　The reader consists of a coil (i.e., "exciter") that forms an electromagnetic field through radio signals. It provides the energy (<1/1000 watt) needed to activate the biochip. The reader has a receiving coil used to receive the ID number or transmission code sent back from the stimulated implanted biochip.

　　 Types of biochips

　　There are three types of biochips: DNA microarrays, microfluidic chips, and protein microarrays.

　　 1) DNA microarrays

　　DNA microarrays or DNA biochips are a set of tiny DNA spots fixed on a solid surface. Researchers use it to calculate the expression levels of a large number of genes. Each DNA marker contains picomoles of a specific gene, which are called probes. In high rigidity, they may be short fragments of genetic material. Usually, probe-target hybridization is observed and counted by identifying fluorescent or chemiluminescent labeled targets to determine the relative abundance of nucleic acid sequences in the target. The innovative nucleic acid array is a macroarray of approximately 9 cm X 12 cm, and the original icon-based automated analysis was released in 1981.

　　 2) Microfluidic chips

　　Microfluidic biochips or lab-on-a-chip are an alternative to traditional biochemical laboratories and are changing many applications such as DNA analysis, molecular biology procedures, proteomics (i.e., protein research), and disease diagnosis (clinical pathology). These chips become more complex by using thousands of components, but the physical design of these components is called a bottom-up fully customized plan, which is a very large labor force.

　 　3) Protein microarrays

　　Protein microarrays or protein chip methods are used to track the activity and connections of proteins and to understand their functions on a large scale. The main advantage of protein microarrays is that we can track a large number of proteins simultaneously. This protein chip consists of a supporting surface such as a microtiter plate or beads, nitrocellulose membrane, glass slide, etc. They are automated, fast, economical, very sensitive, and consume less sample volume. One method of protein chips is the antibody microarray introduced in a 1983 scientific publication. The technology behind this chip is easily developed for DNA microarrays, which have become commonly used microarrays.

　 　Advantages and disadvantages of biochips

　　The advantages of biochips are as follows:

　　Biochips are used to treat patients;

　　Very small size, powerful functions, and faster speed;

　　Biochips help find missing persons;

　　Biochips can be used to individually identify individuals;

　　Biochips perform thousands of biological reactions in seconds.

　　 Biochip applications

　　Applications of biochips include:

　　By using this chip, we can track people or animals anywhere in the world.

　　The chip is used to store and update personal information such as medical, financial, and demographic information.

　　Biochips help build secure e-commerce systems

　　These chips can effectively recover records such as medical, cash, and passports.

　　This biosensor can be used in the medical field as a blood pressure sensor, blood glucose detector, and oxygen sensor.

　　From the information discussed above, we can conclude that biosensors are accurate, fast, and miniaturized. The field of biosensors is at the intersection of chip manufacturing, molecular biology, genomics, and signal processing. The market for biosensors and their applications is growing in many core research areas.